2 Commits

Author SHA1 Message Date
shrutiag14 9dcbc5da00 Merge 2e6303c1f9 into 10872e02d1 2024-06-20 06:47:59 +00:00
shrutiag14 2e6303c1f9 Create C++.txt 2021-05-04 10:31:56 +05:30
17 changed files with 675 additions and 1883 deletions
+16 -42
View File
@@ -1,29 +1,17 @@
<div align="center">
[![AWESOME CHEATSHEETS LOGO](_design/cover_github@2x.png)](https://lecoupa.github.io/awesome-cheatsheets/) [![AWESOME CHEATSHEETS LOGO](_design/cover_github@2x.png)](https://lecoupa.github.io/awesome-cheatsheets/)
<a href="https://trendshift.io/repositories/5584" target="_blank">
<img src="https://trendshift.io/api/badge/repositories/5584" alt="LeCoupa%2Fawesome-cheatsheets | Trendshift" width="250" height="55"/>
</a>
[![Awesome](https://awesome.re/badge.svg)](https://awesome.re) [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/LeCoupa/awesome-cheatsheets/blob/master/LICENSE) [![Awesome](https://awesome.re/badge.svg)](https://awesome.re) [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/LeCoupa/awesome-cheatsheets/blob/master/LICENSE)
**WEBSITE DIRECTORY**: [Available here](https://lecoupa.github.io/awesome-cheatsheets/) **WEBSITE DIRECTORY**: [Available here](https://lecoupa.github.io/awesome-cheatsheets/).
> 📚 Awesome cheatsheets for popular programming languages, frameworks and development tools. They include everything you should know in one single file. > 📚 Awesome cheatsheets for popular programming languages, frameworks and development tools. They include everything you should know in one single file.
</div>
---
## 🤔 Why Awesome-Cheatsheets? ## 🤔 Why Awesome-Cheatsheets?
I usually make a cheat sheet when I want to improve my skills in a programming language, a framework or a development tool. [I started doing these kinds of things a long time ago on Gist](https://gist.github.com/LeCoupa). To better keep track of the history and to let people contribute, I re-organized all of them into this single repository. Most of the content is coming from official documentation and some books I have read. I usually make a cheat sheet when I want to improve my skills in a programming language, a framework or a development tool. [I started doing these kinds of things a long time ago on Gist](https://gist.github.com/LeCoupa). To better keep track of the history and to let people contribute, I re-organized all of them into this single repository. Most of the content is coming from official documentation and some books I have read.
Feel free to take a look. You might learn new things. They have been designed to provide a quick way to assess your knowledge and to save you time. Feel free to take a look. You might learn new things. They have been designed to provide a quick way to assess your knowledge and to save you time.
---
## 📚 Table of Contents ## 📚 Table of Contents
### 📃 Languages ### 📃 Languages
@@ -32,60 +20,59 @@ Feel free to take a look. You might learn new things. They have been designed to
<summary>View cheatsheets</summary> <summary>View cheatsheets</summary>
#### Command line interface #### Command line interface
- [Bash](languages/bash.sh) - [Bash](languages/bash.sh)
#### Imperative #### Imperative
- [C](languages/C.txt) - [C](languages/C.txt)
- [C#](languages/C%23.txt) - [C#](languages/C%23.txt)
- [Go](languages/golang.md) - [Go](languages/golang.md)
- [Java](languages/java.md) - [Java](languages/java.md)
- [PHP](languages/php.php) - [PHP](languages/php.php)
- [Python](languages/python.md) - [Python](languages/python.md)
- [XML](languages/XML.md)
#### Functional #### Functional
- [JavaScript](languages/javascript.js) - [JavaScript](languages/javascript.js)
- [Typescript](languages/typescript.md)
</details> </details>
---
### 📦 Backend ### 📦 Backend
<details> <details>
<summary>View cheatsheets</summary> <summary>View cheatsheets</summary>
#### PHP #### PHP
- [Laravel](backend/laravel.php) - [Laravel](backend/laravel.php)
#### Python #### Python
- [Django](backend/django.py) - [Django](backend/django.py)
#### JavaScript #### Javascript
- [Adonis.js](backend/adonis.js) - [Adonis.js](backend/adonis.js)
- [Express.js](backend/express.js) - [Express.js](backend/express.js)
- [Feathers.js](backend/feathers.js) - [Feathers.js](backend/feathers.js)
- [Moleculer](backend/moleculer.js) - [Moleculer](backend/moleculer.js)
- [Node.js](backend/node.js) - [Node.js](backend/node.js)
- [Sails.js](backend/sails.js) - [Sails.js](backend/sails.js)
</details> </details>
---
### 🌐 Frontend ### 🌐 Frontend
<details> <details>
<summary>View cheatsheets</summary> <summary>View cheatsheets</summary>
#### Basics #### Basics
- [HTML5](frontend/html5.html) - [HTML5](frontend/html5.html)
- [CSS3](frontend/css3.css) - [CSS3](frontend/css3.css)
- [Typescript](frontend/typescript.ts)
#### Frameworks #### Frameworks
- [React.js](frontend/react.js) - [React.js](frontend/react.js)
- [Vue.js](frontend/vue.js) - [Vue.js](frontend/vue.js)
- [Tailwind.css](frontend/tailwind.css) - [Tailwind.css](frontend/tailwind.css)
@@ -94,30 +81,27 @@ Feel free to take a look. You might learn new things. They have been designed to
- [AngularJS](frontend/angularjs.js) - [AngularJS](frontend/angularjs.js)
</details> </details>
---
### 🗃️ Databases ### 🗃️ Databases
<details> <details>
<summary>View cheatsheets</summary> <summary>View cheatsheets</summary>
#### SQL #### SQL
- [MySQL](databases/mysql.sh) - [MySQL](databases/mysql.sh)
#### NoSQL #### NoSQL
- [MongoDB](databases/mongodb.sh)
- [Redis](databases/redis.sh) - [Redis](databases/redis.sh)
</details> </details>
---
### 🔧 Tools ### 🔧 Tools
<details> <details>
<summary>View cheatsheets</summary> <summary>View cheatsheets</summary>
#### Development #### Development
- [cURL](tools/curl.sh) - [cURL](tools/curl.sh)
- [Drush](tools/drush.sh) - [Drush](tools/drush.sh)
- [Elasticsearch](tools/elasticsearch.js) - [Elasticsearch](tools/elasticsearch.js)
@@ -130,35 +114,25 @@ Feel free to take a look. You might learn new things. They have been designed to
- [Xcode](tools/xcode.txt) - [Xcode](tools/xcode.txt)
#### Infrastructure #### Infrastructure
- [AWS CLI](tools/aws.sh) - [AWS CLI](tools/aws.sh)
- [Docker](tools/docker.sh) - [Docker](tools/docker.sh)
- [GCP CLI](tools/gcp.md)
- [Heroku CLI](tools/heroku.sh) - [Heroku CLI](tools/heroku.sh)
- [Kubernetes](tools/kubernetes.md) - [Kubernetes](tools/kubernetes.md)
- [macOS](tools/macos.sh)
- [Nanobox Boxfile](tools/nanobox_boxfile.yml) - [Nanobox Boxfile](tools/nanobox_boxfile.yml)
- [Nanobox CLI](tools/nanobox_cli.sh) - [Nanobox CLI](tools/nanobox_cli.sh)
- [Nginx](tools/nginx.sh) - [Nginx](tools/nginx.sh)
- [PM2](tools/pm2.sh) - [PM2](tools/pm2.sh)
- [Ubuntu](tools/ubuntu.sh) - [Ubuntu](tools/ubuntu.sh)
- [Firebase CLI](tools/firebase_cli.md) - [Firebase CLI](tools/firebase_cli.md)
</details> </details>
---
## 🙌🏼 How to Contribute? ## 🙌🏼 How to Contribute?
You are more than welcome to contribute and build your own cheat sheet for your favorite programming language, framework or development tool. Just submit changes via pull request and I will review them before merging. You are more than welcome to contribute and build your own cheat sheet for your favorite programming language, framework or development tool. Just submit changes via pull request and I will review them before merging.
---
## 👩‍💻👨‍💻 Our valuable Contributors ## 👩‍💻👨‍💻 Our valuable Contributors
<div align="center"> <p align="center"><a href="https://github.com/LeCoupa/awesome-cheatsheets/graphs/contributors">
<a href="https://github.com/LeCoupa/awesome-cheatsheets/graphs/contributors">
<img src="https://contributors-img.web.app/image?repo=LeCoupa/awesome-cheatsheets" /> <img src="https://contributors-img.web.app/image?repo=LeCoupa/awesome-cheatsheets" />
</a> </a></p>
</div>
-96
View File
@@ -16,99 +16,3 @@ GRANT ALL PRIVILEGES ON prospectwith.* TO 'power'@'localhost' WITH GRANT OPTION;
CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password'; # Create user CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password'; # Create user
mysql -u root -pmypassword -e "MY SQL QUERY" &>> query.log & disown # Run SQL query in the background mysql -u root -pmypassword -e "MY SQL QUERY" &>> query.log & disown # Run SQL query in the background
# *****************************************************************************
# Database and Table Operations
# *****************************************************************************
CREATE DATABASE database_name; # Create a new database
DROP DATABASE database_name; # Delete a database
CREATE TABLE table_name (column1 datatype, column2 datatype, ...); # Create a new table
DROP TABLE table_name; # Delete a table
SHOW TABLES; # Display all tables in the current database
DESCRIBE table_name; # Show the structure of a table
# *****************************************************************************
# Data Manipulation
# *****************************************************************************
INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...); # Insert data into a table
UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition; # Update existing data in a table
DELETE FROM table_name WHERE condition; # Delete data from a table
SELECT column1, column2, ... FROM table_name WHERE condition; # Select data from a table
# *****************************************************************************
# Backup and Restore
# *****************************************************************************
mysqldump -u username -p database_name table1 table2 > file.sql # Backup specific tables
mysql -u username -p database_name < file.sql # Restore specific tables
# *****************************************************************************
# User Management and Security
# *****************************************************************************
REVOKE privilege_type ON database_name.table_name FROM 'username'@'hostname'; # Revoke privileges from a user
DROP USER 'username'@'hostname'; # Delete a user
ALTER USER 'username'@'hostname' IDENTIFIED BY 'newpassword'; # Reset a user's password
# *****************************************************************************
# Performance and Maintenance
# *****************************************************************************
OPTIMIZE TABLE table_name; # Optimize a table
ANALYZE TABLE table_name; # Analyze a table for key distribution and storage optimization
CHECK TABLE table_name; # Check a table for errors
REPAIR TABLE table_name; # Repair a corrupted table
# *****************************************************************************
# Advanced Queries
# *****************************************************************************
SELECT ... FROM table1 JOIN table2 ON table1.column = table2.column; # Perform a join operation between two tables
SELECT ... FROM (SELECT ... FROM table_name) AS subquery; # Use a subquery within another query
SELECT column, COUNT(*) FROM table_name GROUP BY column; # Group results and use aggregate functions
# *****************************************************************************
# System Information
# *****************************************************************************
SELECT VERSION(); # Show the current version of MySQL
SELECT User, Host FROM mysql.user; # List all current MySQL users
# *****************************************************************************
# Miscellaneous
# *****************************************************************************
SET GLOBAL general_log = 'ON'; # Enable query logging
SHOW FULL PROCESSLIST; # Show the last queries executed in MySQL
# *****************************************************************************
# Altering Table Structure
# *****************************************************************************
ALTER TABLE table_name ADD COLUMN column_name datatype; # Add a new column to an existing table
ALTER TABLE table_name MODIFY COLUMN column_name datatype; # Change the data type of a column
ALTER TABLE table_name RENAME COLUMN old_name TO new_name; # Rename a column (MySQL 8.0+)
ALTER TABLE table_name DROP COLUMN column_name; # Remove a column from a table
ALTER TABLE old_table_name RENAME TO new_table_name; # Rename an entire table
# *****************************************************************************
# Indexes (Performance Tuning)
# *****************************************************************************
CREATE INDEX idx_name ON table_name (column_name); # Create a standard index to speed up queries
CREATE UNIQUE INDEX idx_name ON table_name (column_name); # Create a unique index (no duplicate values)
SHOW INDEX FROM table_name; # List all indexes on a specific table
DROP INDEX idx_name ON table_name; # Remove an index from a table
EXPLAIN SELECT * FROM table_name WHERE condition; # Analyze how MySQL executes a query (Check index usage)
# *****************************************************************************
# Transactions (Data Integrity)
# *****************************************************************************
START TRANSACTION; # Begin a new transaction
COMMIT; # Save all changes made during the transaction
ROLLBACK; # Undo all changes if an error occurs before commit
SET AUTOCOMMIT = 0; # Disable automatic commits for the current session
SET AUTOCOMMIT = 1; # Re-enable automatic commits after finishing manual transactions
+47 -71
View File
@@ -43,14 +43,11 @@
.hidden /* display: none; */ .hidden /* display: none; */
.block /* display: block; */ .block /* display: block; */
.flow-root /* display: flow-root; */
.inline-block /* display: inline-block; */ .inline-block /* display: inline-block; */
.inline /* display: inline; */ .inline /* display: inline; */
.flex /* display: flex; */ .flex /* display: flex; */
.inline-flex /* display: inline-flex; */ .inline-flex /* display: inline-flex; */
.grid /* display: grid; */ .grid /* display: grid; */
.inline-grid /* display: inline-grid; */
.contents /* display: contents; */
.table /* display: table; */ .table /* display: table; */
.table-caption /* display: table-caption; */ .table-caption /* display: table-caption; */
.table-cell /* display: table-cell; */ .table-cell /* display: table-cell; */
@@ -71,6 +68,7 @@
.float-right /* float: right; */ .float-right /* float: right; */
.float-left /* float: left; */ .float-left /* float: left; */
.float-none /* float: none; */ .float-none /* float: none; */
.clearfix /* &::after { content: ""; display: table; clear: both; } */
/* /*
* Clear * Clear
@@ -132,6 +130,8 @@
.overflow-y-visible /* overflow-y: visible; */ .overflow-y-visible /* overflow-y: visible; */
.overflow-x-scroll /* overflow-x: scroll; */ .overflow-x-scroll /* overflow-x: scroll; */
.overflow-y-scroll /* overflow-y: scroll; */ .overflow-y-scroll /* overflow-y: scroll; */
.scrolling-touch /* -webkit-overflow-scrolling: touch; */
.scrolling-auto /* -webkit-overflow-scrolling: auto; */
/* /*
* Position * Position
@@ -219,7 +219,7 @@
* By default, only responsive variants are generated for flex-wrap utilities. * By default, only responsive variants are generated for flex-wrap utilities.
*/ */
.flex-nowrap /* flex-wrap: nowrap; */ .flex-no-wrap /* flex-wrap: nowrap; */
.flex-wrap /* flex-wrap: wrap; */ .flex-wrap /* flex-wrap: wrap; */
.flex-wrap-reverse /* flex-wrap: wrap-reverse; */ .flex-wrap-reverse /* flex-wrap: wrap-reverse; */
@@ -478,44 +478,44 @@
.gap-56 /* gap: 14rem; */ .gap-56 /* gap: 14rem; */
.gap-64 /* gap: 16rem; */ .gap-64 /* gap: 16rem; */
.gap-px /* gap: 1px; */ .gap-px /* gap: 1px; */
.gap-y-0 /* row-gap: 0; */ .row-gap-0 /* row-gap: 0; */
.gap-y-1 /* row-gap: 0.25rem; */ .row-gap-1 /* row-gap: 0.25rem; */
.gap-y-2 /* row-gap: 0.5rem; */ .row-gap-2 /* row-gap: 0.5rem; */
.gap-y-3 /* row-gap: 0.75rem; */ .row-gap-3 /* row-gap: 0.75rem; */
.gap-y-4 /* row-gap: 1rem; */ .row-gap-4 /* row-gap: 1rem; */
.gap-y-5 /* row-gap: 1.25rem; */ .row-gap-5 /* row-gap: 1.25rem; */
.gap-y-6 /* row-gap: 1.5rem; */ .row-gap-6 /* row-gap: 1.5rem; */
.gap-y-8 /* row-gap: 2rem; */ .row-gap-8 /* row-gap: 2rem; */
.gap-y-10 /* row-gap: 2.5rem; */ .row-gap-10 /* row-gap: 2.5rem; */
.gap-y-12 /* row-gap: 3rem; */ .row-gap-12 /* row-gap: 3rem; */
.gap-y-16 /* row-gap: 4rem; */ .row-gap-16 /* row-gap: 4rem; */
.gap-y-20 /* row-gap: 5rem; */ .row-gap-20 /* row-gap: 5rem; */
.gap-y-24 /* row-gap: 6rem; */ .row-gap-24 /* row-gap: 6rem; */
.gap-y-32 /* row-gap: 8rem; */ .row-gap-32 /* row-gap: 8rem; */
.gap-y-40 /* row-gap: 10rem; */ .row-gap-40 /* row-gap: 10rem; */
.gap-y-48 /* row-gap: 12rem; */ .row-gap-48 /* row-gap: 12rem; */
.gap-y-56 /* row-gap: 14rem; */ .row-gap-56 /* row-gap: 14rem; */
.gap-y-64 /* row-gap: 16rem; */ .row-gap-64 /* row-gap: 16rem; */
.gap-y-px /* row-gap: 1px; */ .row-gap-px /* row-gap: 1px; */
.gap-x-0 /* column-gap: 0; */ .col-gap-0 /* column-gap: 0; */
.gap-x-1 /* column-gap: 0.25rem; */ .col-gap-1 /* column-gap: 0.25rem; */
.gap-x-2 /* column-gap: 0.5rem; */ .col-gap-2 /* column-gap: 0.5rem; */
.gap-x-3 /* column-gap: 0.75rem; */ .col-gap-3 /* column-gap: 0.75rem; */
.gap-x-4 /* column-gap: 1rem; */ .col-gap-4 /* column-gap: 1rem; */
.gap-x-5 /* column-gap: 1.25rem; */ .col-gap-5 /* column-gap: 1.25rem; */
.gap-x-6 /* column-gap: 1.5rem; */ .col-gap-6 /* column-gap: 1.5rem; */
.gap-x-8 /* column-gap: 2rem; */ .col-gap-8 /* column-gap: 2rem; */
.gap-x-10 /* column-gap: 2.5rem; */ .col-gap-10 /* column-gap: 2.5rem; */
.gap-x-12 /* column-gap: 3rem; */ .col-gap-12 /* column-gap: 3rem; */
.gap-x-16 /* column-gap: 4rem; */ .col-gap-16 /* column-gap: 4rem; */
.gap-x-20 /* column-gap: 5rem; */ .col-gap-20 /* column-gap: 5rem; */
.gap-x-24 /* column-gap: 6rem; */ .col-gap-24 /* column-gap: 6rem; */
.gap-x-32 /* column-gap: 8rem; */ .col-gap-32 /* column-gap: 8rem; */
.gap-x-40 /* column-gap: 10rem; */ .col-gap-40 /* column-gap: 10rem; */
.gap-x-48 /* column-gap: 12rem; */ .col-gap-48 /* column-gap: 12rem; */
.gap-x-56 /* column-gap: 14rem; */ .col-gap-56 /* column-gap: 14rem; */
.gap-x-64 /* column-gap: 16rem; */ .col-gap-64 /* column-gap: 16rem; */
.gap-x-px /* column-gap: 1px; */ .col-gap-px /* column-gap: 1px; */
/* /*
* Grid Auto Flow * Grid Auto Flow
@@ -1153,8 +1153,8 @@
* By default, only responsive, hover and focus variants are generated for font weight utilities. * By default, only responsive, hover and focus variants are generated for font weight utilities.
*/ */
.font-thin /* font-weight: 100; */ .font-hairline /* font-weight: 100; */
.font-extralight /* font-weight: 200; */ .font-thin /* font-weight: 200; */
.font-light /* font-weight: 300; */ .font-light /* font-weight: 300; */
.font-normal /* font-weight: 400; */ .font-normal /* font-weight: 400; */
.font-medium /* font-weight: 500; */ .font-medium /* font-weight: 500; */
@@ -1479,7 +1479,7 @@
*/ */
.whitespace-normal /* white-space: normal; */ .whitespace-normal /* white-space: normal; */
.whitespace-nowrap /* white-space: nowrap; */ .whitespace-no-wrap /* white-space: nowrap; */
.whitespace-pre /* white-space: pre; */ .whitespace-pre /* white-space: pre; */
.whitespace-pre-line /* white-space: pre-line; */ .whitespace-pre-line /* white-space: pre-line; */
.whitespace-pre-wrap /* white-space: pre-wrap; */ .whitespace-pre-wrap /* white-space: pre-wrap; */
@@ -1902,6 +1902,7 @@
* By default, only responsive, hover and focus variants are generated for box shadow utilities. * By default, only responsive, hover and focus variants are generated for box shadow utilities.
*/ */
.shadow-xs /* box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.05); */
.shadow-sm /* box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05); */ .shadow-sm /* box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05); */
.shadow /* box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06); */ .shadow /* box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06); */
.shadow-md /* box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06); */ .shadow-md /* box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06); */
@@ -1909,34 +1910,9 @@
.shadow-xl /* box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04); */ .shadow-xl /* box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04); */
.shadow-2xl /* box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25); */ .shadow-2xl /* box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25); */
.shadow-inner /* box-shadow: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06); */ .shadow-inner /* box-shadow: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06); */
.shadow-outline /* box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.5); */
.shadow-none /* box-shadow: none; */ .shadow-none /* box-shadow: none; */
/*
* RING
* --------------------
* Utilities for creating outline rings with box-shadows.
* Replaced the old .shadow-outline utility.
*/
.ring-0 /* box-shadow: 0 0 0 0px; */
.ring-1 /* box-shadow: 0 0 0 1px; */
.ring-2 /* box-shadow: 0 0 0 2px; */
.ring-4 /* box-shadow: 0 0 0 4px; */
.ring-8 /* box-shadow: 0 0 0 8px; */
.ring /* box-shadow: 0 0 0 3px; */
.ring-inset /* --ring-inset: inset; */
.ring-transparent /* --ring-color: transparent; */
.ring-black /* --ring-color: #000; */
.ring-white /* --ring-color: #fff; */
.ring-current /* --ring-color: currentColor; */
.ring-offset-0 /* --ring-offset-width: 0px; */
.ring-offset-1 /* --ring-offset-width: 1px; */
.ring-offset-2 /* --ring-offset-width: 2px; */
.ring-offset-4 /* --ring-offset-width: 4px; */
.ring-offset-8 /* --ring-offset-width: 8px; */
/* /*
* OPACITY * OPACITY
* -------------------- * --------------------
-670
View File
@@ -1,670 +0,0 @@
/****************************
* TYPESCRIPT CHEATSHEET - Quick Reference
* Learn more: https://www.typescriptlang.org/docs/
* Playground: https://www.typescriptlang.org/play
* Handbook: https://www.typescriptlang.org/handbook/
*
* Table of contents
* -------------------
* 01 | Basic Types
* 02 | Variables & Arrays
* 03 | Functions
* 04 | Objects & Interfaces
* 05 | Classes
* 06 | Generics
* 07 | Union & Literal Types
* 08 | Type Guards & Assertions
* 09 | Utility Types
* 10 | Enums
* 11 | Modules
* 12 | Advanced Types
* 13 | Decorators
* 14 | Configuration
* 15 | Common Patterns
*****************************/
/***************************
------------ 01: Basic Types -----------
*******************************/
// Primitive Types
let str: string = "hello";
let num: number = 42;
let bool: boolean = true;
let undef: undefined = undefined;
let nul: null = null;
// Special Types
let anything: any = "can be anything";
let unknown: unknown = "type-safe any";
let nothing: void = undefined;
let never: never = (() => { throw new Error() })();
// Type Inference
let auto = "TypeScript infers string";
let nums = [1, 2, 3]; // number[]
/***************************
------------ 02: Variables & Arrays -----------
*******************************/
// Arrays
let numbers: number[] = [1, 2, 3];
let strings: Array<string> = ["a", "b"];
let mixed: (string | number)[] = [1, "two"];
// Tuples
let tuple: [string, number] = ["hello", 42];
let namedTuple: [name: string, age: number] = ["John", 30];
// Destructuring
let [first, second] = tuple;
let [x, y, ...rest] = [1, 2, 3, 4, 5];
// Object Destructuring
let {name, age} = {name: "John", age: 30};
let {a: newName, b = 10} = {a: "value"}; // rename & default
/***************************
------------ 03: Functions -----------
*******************************/
// Function Declaration
function add(x: number, y: number): number {
return x + y;
}
// Arrow Functions
const multiply = (x: number, y: number): number => x * y;
const greet = (name: string): void => console.log(`Hello ${name}`);
// Optional & Default Parameters
function build(first: string, last?: string, age = 25): string {
return `${first} ${last || ""} (${age})`;
}
// Rest Parameters
function sum(...nums: number[]): number {
return nums.reduce((a, b) => a + b, 0);
}
// Function Overloads
function format(x: string): string;
function format(x: number): string;
function format(x: string | number): string {
return x.toString();
}
// Function Types
type MathOp = (x: number, y: number) => number;
const divide: MathOp = (x, y) => x / y;
/***************************
------------ 04: Objects & Interfaces -----------
*******************************/
// Object Types
let person: {name: string, age: number} = {name: "John", age: 30};
// Interface
interface User {
readonly id: number;
name: string;
email?: string; // optional
[key: string]: any; // index signature
}
// Extending Interfaces
interface Admin extends User {
permissions: string[];
}
// Multiple Inheritance
interface Timestamped {
createdAt: Date;
}
interface AdminUser extends User, Timestamped {
role: "admin";
}
// Function in Interface
interface Calculator {
add(x: number, y: number): number;
subtract: (x: number, y: number) => number;
}
/***************************
------------ 05: Classes -----------
*******************************/
// Basic Class
class Animal {
public name: string;
private age: number;
protected species: string;
readonly id: number;
constructor(name: string, age: number) {
this.name = name;
this.age = age;
this.species = "unknown";
this.id = Math.random();
}
speak(): void {
console.log(`${this.name} makes a sound`);
}
}
// Inheritance
class Dog extends Animal {
breed: string;
constructor(name: string, age: number, breed: string) {
super(name, age);
this.breed = breed;
}
speak(): void {
console.log(`${this.name} barks`);
}
}
// Abstract Class
abstract class Shape {
abstract area(): number;
display(): void {
console.log(`Area: ${this.area()}`);
}
}
// Static Members
class MathUtils {
static PI = 3.14159;
static circle(radius: number): number {
return 2 * MathUtils.PI * radius;
}
}
// Getters/Setters
class Person {
private _age: number = 0;
get age(): number {
return this._age;
}
set age(value: number) {
if (value >= 0) this._age = value;
}
}
/***************************
------------ 06: Generics -----------
*******************************/
// Generic Functions
function identity<T>(arg: T): T { return arg; }
const result = identity<string>("hello");
const inferred = identity(42); // T inferred as number
// Multiple Type Parameters
function pair<T, U>(first: T, second: U): [T, U] {
return [first, second];
}
// Generic Interface
interface Container<T> {
value: T;
getValue(): T;
}
// Generic Class
class Box<T> {
contents: T;
constructor(value: T) {
this.contents = value;
}
}
// Constraints
interface HasLength {
length: number;
}
function logLength<T extends HasLength>(arg: T): void {
console.log(arg.length);
}
// Keyof Constraint
function getProperty<T, K extends keyof T>(obj: T, key: K): T[K] {
return obj[key];
}
/***************************
------------ 07: Union & Literal Types -----------
*******************************/
// Union Types
type StringOrNumber = string | number;
type Status = "loading" | "success" | "error";
function process(id: string | number): void {
if (typeof id === "string") {
console.log(id.toUpperCase());
} else {
console.log(id.toFixed(2));
}
}
// Intersection Types
type Person = {name: string};
type Employee = {company: string};
type Staff = Person & Employee; // has both properties
// Literal Types
type Theme = "light" | "dark";
type Port = 3000 | 8080 | 9000;
type Success = true;
// Discriminated Unions
interface Circle {
kind: "circle";
radius: number;
}
interface Square {
kind: "square";
sideLength: number;
}
type Shape = Circle | Square;
function area(shape: Shape): number {
switch (shape.kind) {
case "circle":
return Math.PI * shape.radius ** 2;
case "square":
return shape.sideLength ** 2;
}
}
/***************************
------------ 08: Type Guards & Assertions -----------
*******************************/
// Type Guards
function isString(value: any): value is string {
return typeof value === "string";
}
function isNumber(value: any): value is number {
return typeof value === "number";
}
// Using Type Guards
function process(value: string | number) {
if (isString(value)) {
console.log(value.toUpperCase()); // TypeScript knows it's string
} else {
console.log(value.toFixed(2)); // TypeScript knows it's number
}
}
// in operator
type Fish = { swim: () => void };
type Bird = { fly: () => void };
function move(animal: Fish | Bird) {
if ("swim" in animal) {
animal.swim(); // Fish
} else {
animal.fly(); // Bird
}
}
// instanceof
function handleError(error: Error | string) {
if (error instanceof Error) {
console.log(error.message);
} else {
console.log(error);
}
}
// Type Assertions
let someValue: any = "hello world";
let strLength = (someValue as string).length;
// or: let strLength = (<string>someValue).length;
// Non-null Assertion
let name: string | null = getName();
let nameLength = name!.length; // Assert name is not null
/***************************
------------ 09: Utility Types -----------
*******************************/
interface Todo {
title: string;
description: string;
completed: boolean;
}
// Partial<T> - All properties optional
type PartialTodo = Partial<Todo>;
// {title?: string, description?: string, completed?: boolean}
// Required<T> - All properties required
type RequiredTodo = Required<PartialTodo>;
// Readonly<T> - All properties readonly
type ReadonlyTodo = Readonly<Todo>;
// Pick<T, K> - Select specific properties
type TodoPreview = Pick<Todo, "title" | "completed">;
// Omit<T, K> - Exclude specific properties
type TodoInfo = Omit<Todo, "completed">;
// Record<K, T> - Create object type
type TodoStatus = Record<"pending" | "completed", Todo[]>;
// Exclude<T, U> - Remove types from union
type NonString = Exclude<string | number | boolean, string>;
// number | boolean
// Extract<T, U> - Extract types from union
type StringOnly = Extract<string | number | boolean, string>;
// string
// NonNullable<T> - Remove null/undefined
type NonNullString = NonNullable<string | null | undefined>;
// string
// ReturnType<T> - Get function return type
function getName(): string { return "John"; }
type NameType = ReturnType<typeof getName>; // string
// Parameters<T> - Get function parameters as tuple
type GetNameParams = Parameters<typeof getName>; // []
/***************************
------------ 10: Enums -----------
*******************************/
// Numeric Enum
enum Direction {
Up, // 0
Down, // 1
Left, // 2
Right // 3
}
// String Enum
enum Color {
Red = "red",
Green = "green",
Blue = "blue"
}
// Mixed Enum
enum Mixed {
No = 0,
Yes = "yes"
}
// Const Enum (inlined at compile time)
const enum StatusCode {
OK = 200,
NotFound = 404,
Error = 500
}
// Usage
let currentDirection = Direction.Up;
let favoriteColor = Color.Blue;
let status = StatusCode.OK;
/***************************
------------ 11: Modules -----------
*******************************/
// Named Exports
export const PI = 3.14159;
export function calculate(r: number): number {
return PI * r * r;
}
export class Calculator {
add(x: number, y: number): number { return x + y; }
}
// Default Export
export default class Logger {
log(message: string): void {
console.log(message);
}
}
// Re-exports
export { Calculator as Calc } from "./calculator";
export * from "./utilities";
// Import
import Logger from "./logger"; // default import
import { PI, calculate } from "./math"; // named imports
import * as MathUtils from "./math"; // namespace import
import { Calculator as Calc } from "./calculator"; // alias
// Dynamic Imports
const module = await import("./dynamic-module");
/***************************
------------ 12: Advanced Types -----------
*******************************/
// Mapped Types
type Nullable<T> = {
[P in keyof T]: T[P] | null;
};
type OptionalId<T> = {
[P in keyof T]: P extends "id" ? T[P] | undefined : T[P];
};
// Conditional Types
type IsString<T> = T extends string ? true : false;
type StringCheck = IsString<"hello">; // true
// Template Literal Types
type EventName<T extends string> = `on${Capitalize<T>}`;
type ClickEvent = EventName<"click">; // "onClick"
// Indexed Access Types
type Person = { name: string; age: number; location: string };
type PersonName = Person["name"]; // string
type PersonKeys = keyof Person; // "name" | "age" | "location"
// Recursive Types
type Json = string | number | boolean | null | Json[] | {[key: string]: Json};
/***************************
------------ 13: Decorators -----------
*******************************/
// Class Decorator
function Component(name: string) {
return function<T extends {new(...args: any[]): {}}>(constructor: T) {
return class extends constructor {
componentName = name;
};
};
}
@Component("MyComponent")
class MyClass {}
// Method Decorator
function Log(target: any, propertyName: string, descriptor: PropertyDescriptor) {
const method = descriptor.value;
descriptor.value = function(...args: any[]) {
console.log(`Calling ${propertyName} with`, args);
return method.apply(this, args);
};
}
class Service {
@Log
getData(): string {
return "data";
}
}
// Property Decorator
function MinLength(length: number) {
return function(target: any, propertyName: string) {
let value: string;
const getter = () => value;
const setter = (newVal: string) => {
if (newVal.length < length) {
throw new Error(`${propertyName} must be at least ${length} chars`);
}
value = newVal;
};
Object.defineProperty(target, propertyName, {
get: getter,
set: setter
});
};
}
class User {
@MinLength(3)
username: string;
}
/***************************
------------ 14: Configuration -----------
*******************************/
// tsconfig.json
/*
{
"compilerOptions": {
"target": "ES2020",
"module": "commonjs",
"lib": ["ES2020", "DOM"],
"outDir": "./dist",
"rootDir": "./src",
"strict": true,
"esModuleInterop": true,
"skipLibCheck": true,
"forceConsistentCasingInFileNames": true,
"moduleResolution": "node",
"allowSyntheticDefaultImports": true,
"experimentalDecorators": true,
"emitDecoratorMetadata": true,
"sourceMap": true,
"declaration": true,
"removeComments": true,
"noImplicitAny": true,
"noImplicitReturns": true,
"noUnusedLocals": true,
"noUnusedParameters": true
},
"include": ["src/**/*"],
"exclude": ["node_modules", "dist"]
}
*/
// Compiler Options Quick Reference
// --target: ES5, ES6, ES2017, ES2018, ES2019, ES2020, ESNext
// --module: commonjs, amd, es2015, es2020, esnext, system, umd
// --lib: ES5, ES6, ES2017, DOM, WebWorker, ScriptHost
// --strict: Enable all strict type checking options
/***************************
------------ 15: Common Patterns -----------
*******************************/
// API Response Type
interface ApiResponse<T> {
data: T;
status: number;
message: string;
}
// Event Handler Pattern
type EventHandler<T = Event> = (event: T) => void;
const onClick: EventHandler<MouseEvent> = (e) => console.log(e.clientX);
// Builder Pattern
class QueryBuilder {
private query = "";
select(fields: string): this {
this.query += `SELECT ${fields} `;
return this;
}
from(table: string): this {
this.query += `FROM ${table} `;
return this;
}
build(): string {
return this.query.trim();
}
}
// Factory Pattern
interface Shape { area(): number; }
class Circle implements Shape {
constructor(private radius: number) {}
area(): number { return Math.PI * this.radius ** 2; }
}
class ShapeFactory {
static createCircle(radius: number): Shape {
return new Circle(radius);
}
}
// Promise/Async Patterns
type AsyncResult<T> = Promise<T | Error>;
async function fetchUser(id: number): Promise<User | null> {
try {
const response = await fetch(`/api/users/${id}`);
return await response.json();
} catch {
return null;
}
}
// Type-safe Environment Variables
interface Env {
NODE_ENV: "development" | "production" | "test";
PORT: number;
DATABASE_URL: string;
}
declare global {
namespace NodeJS {
interface ProcessEnv extends Env {}
}
}
/*
* QUICK TIPS
* ----------
* • Use 'unknown' instead of 'any' when possible
* • Prefer 'interface' for object shapes, 'type' for unions/computed types
* • Enable strict mode in tsconfig.json
* • Use const assertions: const colors = ['red', 'blue'] as const
* • Prefer type guards over type assertions
* • Use utility types instead of manual type manipulation
* • Enable noImplicitAny for better type safety
* • Use discriminated unions for complex state management
*/
+8 -8
View File
@@ -88,7 +88,7 @@ CHEATSHEET C#
string newStr = oldStr.Replace("old","new"); string newStr = oldStr.Replace("old","new");
//IndexOf //IndexOf
//Finds the first occurrence of a string in a larger string //Finds the first ocurrence of a string in a larger string
//Returns -1 if the string is not found //Returns -1 if the string is not found
String.IndexOf(val, start, num) String.IndexOf(val, start, num)
val - string to search for val - string to search for
@@ -102,7 +102,7 @@ CHEATSHEET C#
String.Split(Char[]); String.Split(Char[]);
//ToCharArray //ToCharArray
//Places selected characters in a string in a char array //Places selected characteres in a string in a char array
String str = "AaBbCcDd"; String str = "AaBbCcDd";
//create array of 8 vowels //create array of 8 vowels
var chars = str.ToCharArray(); var chars = str.ToCharArray();
@@ -135,7 +135,7 @@ CHEATSHEET C#
6.1 TimeSpan Constructor 6.1 TimeSpan Constructor
TimeSpan(hour, minute, sec) TimpeSpan(hour, minute, sec)
TimeSpan timeS = new TimeSpan(10, 14, 50); TimeSpan timeS = new TimeSpan(10, 14, 50);
TimeSpan timeS_Hours = TimeSpan.FromDays(3640); TimeSpan timeS_Hours = TimeSpan.FromDays(3640);
@@ -144,8 +144,8 @@ CHEATSHEET C#
Format item syntax: {index[,alignment][:format string]} Format item syntax: {index[,alignment][:format string]}
index - Specifies element in list of values to which format is applied index - Specifies element in list of values to which format is applied
alignment - Indicates minimum width (in characters) to display value aligment - Indicates minimun width (in characters) to display value
format string - Contains the code which specifies the format of the displayed value format string - Contains the code which specififes the format of the displayed value
7.1 Numeric 7.1 Numeric
@@ -293,7 +293,7 @@ CHEATSHEET C#
[access modifier] className (parameters) [:initializer] [access modifier] className (parameters) [:initializer]
initializer -base calls constructor in base class. initializer -base calls constructor in base class.
this calls constructor within class. this calls constuctor within class.
public class nameClass : Initializer { public class nameClass : Initializer {
public className(dataType param1 , dataType param2, ...) : base(param1, param2) public className(dataType param1 , dataType param2, ...) : base(param1, param2)
@@ -313,8 +313,8 @@ CHEATSHEET C#
abstract must be implemented by subclass abstract must be implemented by subclass
Passing parameters: Passing parameters:
1. By default, parameters are passed by value 1. By default, parametres are passed by value
2. Passing by reference: ref, in and out modifiers 2. Passing by reference: ref, in and out modifers
To pass a parameter by reference with the intent of changing the value, use the ref, or out keyword. To pass by reference with the intent of avoiding copying but not changing the value, use the in modifier To pass a parameter by reference with the intent of changing the value, use the ref, or out keyword. To pass by reference with the intent of avoiding copying but not changing the value, use the in modifier
+485
View File
@@ -0,0 +1,485 @@
#DATA TYPES
1)void - type with empty set of values.There is no structure assosciated with void except pointers.
std::nullptr_t is a special pointer that is not itself a pointer type.
2) int - stores an integer value .
4 bytes C++ standard since C11. (for 16-bit OS its 2 bytes)
Hence,int value ranges from -2147483648 to 2147483647.
3) float - stores an decimal value.
4 bytes .
4) char - stores a single character value(ASCII values)
1 byte.(0 to 255)
5) bool - stores a boolean value.(true or false)
1 byte.
stores a value 0 or 1 indicating tue or false.
# MODIFIERS
C++ has modifiers for extending the limits of the basic data types for some advanced calculation.There are 2 types of Modifiers:-
1)Signedness
# signed - by default,target will have signed representation ,which means a variable can take negative values.
# unsigned - target data type will be unsigned means only positive(absolute) values will be taken by that type.
2) Size
# short - Target data type will have a width of atleast 2 bytes.The data type is optimized for lower bounds using less space.
# long - Target data type will have a width of atleast 4 bytes.
# long long - Target data type will have a width of at least 8 bytes.
Character Types
1) signed char
2) unsigned char
3) char
4) wchar_t
Float Types
1) float
2) double
3) long double
# DATA STRUCTURES
1) ARRAYS
to declare an array of any type : data_type name_of_array[size of array];
array cannot be re-intialized with the number of elements.
2) LINKED LIST
a linked list in cpp is built-in in the form of vectors
to declare an vector(linked list) in cpp : vector<data_type> name;
you have to include vector library. #include<vector>
3) STACK
to make a stack in cpp : stack<data_type> name;
you have to include stack library .#include<stack>
4) QUEUE
to make a queue in cpp : queue<data_type> name;
you have to include queue library .#include<queue>
cout<<"Anything"<<variables<<endl;
* This prints text on console (Console OUTput).
cin>>x;
* This inputs data from user and stores in specified variables.
cin.getline(variable,characters in it)
* This is specially used for white sapced (Spaces) input.
* Declare a variable named x
DataType Description
int x; // Integer var named x
char x; // Character var stores one alphabet,numerics,special symbol and is one byte.
string x; // Characterd back to back
bool x; // Boolean value (1 or 0)(true or false)
float x; // Real values (decimal numbers)
*
#KEYWORDS (reserved words ,have special functionality).There are 97 keywords in C++ as of C20 standard.
1) alignas -specifies the alignment requirement of a type or an object.
2) alignof -queries alignment requirements of a type.
3) and -logical and operator.(alternative to &&)
4) and_eq -bitwise and operator .(alternative to &= ,x&=y or x=x&y)
5) asm -embed assembly code within C++ program.
6) atomic_cancel -
7) atomic_commit -
8) atomic_noexcept
9) auto -automatic intializer or return type evaluated.
10) bitand -alternative for bitwise and. (&)
11) bitor -alternative for bitwise or. (|)
12) bool -data type,capable of holding either true or false.
13) break -terminating statement for, loops and switch statements.
14) case -transfer control to one of the several statements depending on the value of conditions.
15) catch -used in exception handling.
16) char -data type character.
17) char8_t -character data type 1 byte.(UTF-8 bit character)
18) char16_t -character data type 2 bytes.(UTF-16 bit character)
19) char32_t -character data type 4 bytes.(UTF-32 bit character)
20) class -declaration of user-defined data types.
21) compl -compliment operator.(alternative to ~)
22) concept -named set of requirements.
23) const -defines that the type is constant.
24) consteval -specifies that a function is an immediate function.
25) constexpr -specifies that the value of a variable or function can appear in constant expression.
26) constinit -asserts that a variable has static intialization.
27) const_cast -converts between types with different cv-qualification.
28) continue -causes the remaining body of loops to be skipped.
29) co_await -suspend operation until resumed.
30) co_return -complete execution returning a value.
31) co_yield -suspend execution returning a value.
32) decltype -inspects the declared type of an entity or the type and value category of an expression.
33) default -transfer control to one of the several statements,explicitly defaultedfunction definition.
34) delete -destroy previously allocated objects,ill-formed functions.
35) do -do-while loop.(executes a statement repeatedly,until condition is false)
36) double -double precision floating point.
37) dynamic_cast -safely converts pointers and references to classes along the inheritance hierarchy.
38) else -if the bool value of if() is false then this block gets executed.
39) enum -enumeration is a distinct type whose value is restricted to a range of values.
40) explicit -specifies that a constructor or conversion function cannot be used for implicit conversions and copy initialization.
41) export -exports all namespace-scope declaration.
42) extern -applies the language specification for external linkages of function names,types and variables.
43) false -a boolean literal indicating condition is not satisfied.
44) float -data type declaration for floating point numbers.
45) for -intializes counter once and iterates over and over again incrementing the counter each time ,till the condition is met.Range based for loop executes over a range.
46) friend -a friend declaration appears in a class body to grants a function or another class access to private and protected members.
47) goto -transfers control unconditionally.
48) if -if the condition yields true then the block of code gets executed.
49) inline -declares a function to be inline function .
50) int -basic integer data type.
51) long -target type will have a width of atleast 4 bytes.
52) mutable -permits modification of class members even if they are declared const.
53) namespace -provide a method for preventing name conflicts in large projects.
54) new -creates and initializes objects with dynamic storage duration.
55) noexcept -performs a compile time check that returns true if an expression is declared not to throw exceptions.
56) not -alternative operator for !
57) not_eq -alternative operator for !=
58) null_ptr -denotes a pointer literal.
59) operator -customizes C++ operators for operands of user-defined data type
60) or -alternative to | operator.
61) or_eq -alternative to |= operator.
62) private -member specification of class/struct or union ,define the accessibility of subsequent members.
63) protected -member specification of class/struct or union ,define the accessibility of subsequent members and inherited members of base class.
64) public - member specification of class/struct or union ,define the accessibility of subsequent members to any subsequent class.
65) reflexpr -
66) register -automatic storage duration.
67) reinterpret_cast -converts between types by reinterpreting the underlying bit pattern.
68) requires -used to introduce a requires-clause, which specifies constraints on template arguments or on a function declaration.
69) return -terminates the current function and gives back a specified value to the caller.
70) short -target type will be optimized for space and will have a width of 2 bytes atleast.
71) signed -target will have a signed representation.
72) sizeof -used when actual size of object must be known.
73) static -specified variables will have static storage duration.
74) static_asset -performs compile-time assertion check.
75) static_cast -converts between types using a combination of implicit and user-defined conversions.
76) struct -class with public member accessibility by default.
77) switch -transfer control to one of the several statements,depending on the value of condition.
78) synchronized -
79) template -template is an entity of family of either classes,functions or variables.
80) this -a prvalue expression whose value is the address of the implicit object parameter.
81) thread_local -thread storage duration.
82) throw -signals and erroneous conditions and executes an error handler.
83) true -a boolean literal indicating condition is satisfied.
84) try -associates one or more exception handlers with a compound statement.
85) typedef -creates an alias that can be used anywhere in place of a type name.
86) typeid -used where the dynamic type or polymorphic object must be known and for static type identification.
87) typename -similar word for class.
88) union -a special class type that can hold only one of its non-static data members at a time.
89) unsigned -target type will have a unsigned representation.
90) using -introduces a name that is defines elsewhere into the declarative region .
91) virtual -virtual functions or classes are defined using the virtual keyword.
92) void -type with empty set of values.
93) volatile -defines that the type is volatile.
94) wchar_t -type for wide character representation.
95) while -executes statements repeatedly untill the condition becomes false.
96) xor -alternative operator for ^
97) xor_eq -alternative operatir for ^=
#HEADER FILES
#include<files>
*This makes the compiler aware that other files are required for the complete working of this source code.
List of Header files and their respective functions in C++
1) <cstdlib> General purpose library.
Function name use cases return type Parameters
malloc allocates memory void* 1(number of bytes)
calloc allocates and zeroes memory void* 2(no.of obj,size of each obj)
realloc expands or shrinks previously allocated memory void* 2(pointer to mem area allocated,new size of array)
free deallocates previously allocated memory void 1(pointer to memory to deallocate)
atof converts a byte string to floating point value double 1(string)
atoll converts a byte string to integer value int/long/long long 1(string)
strtoull converts a byte string to unsigned integer long/long long 3(str ,str_end ,base)
strtold convert a byte string to a float point value float/double/lonng double 2(str ,str_end)
rand generate pseudo-random numbers int 0
srand seeds pseudo-random number generation void 1(seed)
qsort sorts range of element with unspecified type. void 4(ptr ,count ,size ,comp)
bsearch searches an array for an element of unspecified type. void* 5(key ,ptr ,count ,size ,comp)
abs/llabs completes absolute value of an integer value. int/long/long long 1(int)
lldiv computes quotient and remainder of integer division obj 2(int,int)
abort abnormal program termination without cleaning up. void 0
exit normal program termination with cleaning up. void 1(exit_code)
mblen returns number of bytes in next multibyte characters. int 2(ptr ,int)
mbtowc converts a next multilayer character to wide characters. int 3(int , ptr , ptr)
wctomb converts a next multilayer character to wide characters. int 2(wide char , ptr)
2) <bitset> general utility library
operator& performs binary logic operations on bitsets.(and)
operator| performs binary logic operations on bitsets.(or) }obj 2(lhs ,rhs)
operator^ performs binary logic operations on bitsets.(xor)
operator>> performs stream output of bitsets
operator<< performs stream input of bitsets
3) <utility> general utility library
swap swaps the value of two objects. obj 2(a ,b)
exchange replaces the argument with a new value and returns its previous value. obj 2(obj , new_obj)
forward forwards a function argument. obj 1(obj)
move obtains an rvalue refrence. obj 1(obj)
std::get access an element of a pair. refernce (ptr) 1(obj)
operator<=> lexicographically compares the value in pair. boolean 2(lhs , rhs)
in_range checks if an integer value is in the range of a given integer type. boolean 1(obj)
cmp_equal
cmp_not_equal
cmp_less } compares two integer values without value change caused by conversion. boolean 2(u , t )
cmp_greater
cmp_less_equal
cmp_greater_equal
4) <functional> provudes standard hash functions
bind_front binds a variable number of arguments,in order,to a function object. obj 2(obj , args)
bind binds one or more arguments to a function object. obj 2(obj , args)
ref/cref creates a std::reference_wrapper with a type deduced from its argument. obj 1(ptr to obj)
invoke invokes any callable object with given arguments. obj 2(obj , args)
5) <ctime> C-style time/date utility.
clock returns raw processor clock time since the program started. int (time) 0
time returns the current time of the system since epoch. obj 1(ptr)
difftime computes the difference between times. int (time) 2(time_begin , time_end)
time_spec_get returns the calender time based on a given time base. int 2(ptr , base)
6) <chrono> C++ time/date utility
opeartors
+
-
* }implements arithmetic operations with durations as arguments. obj 4(lhs , rhs , d , s)
/
%
operators
==
<
> }compares two durations. obj 2(lhs , rhs )
<=
>=
<=>
duration cast converts a duration to another. time duration(int ,float,etc) 1(duration time)
floor converts a duration to another,rounding down. time duration(int ,float,etc) 1(duration time)
ceil converts a duration to another,rounding up. time duration(int ,float,etc) 1(duration time)
round converts a duration to another,rounding to nearest,ties to even. time duration(int ,float,etc) 1(duration time)
abs obtain the absolute value of the duration. time duration(int ,float,etc) 1(duration time)
7) <algorithm>
all_of
any_of } checks for any predicate is true for elements in a range. boolean 4(first ,last, policy ,predicate)
none_of
for_each applies a function to a range of elements obj 4(first ,last, policy ,obj)
for_each_n applies a function to a range of n elements in a sequence integer 4(first ,last, policy ,obj)
count }returns the number of elements satisfying a criteria. integer 4(first ,last, policy ,predicate)
count_if
mismatch finds first position where two ranges differ. obj 6(first1 ,last1 ,first2 ,last2 ,policy ,binary predicate)
find
find_if }finds first element which satisfies specific criteria. obj 6(first, last ,policy ,valur,unary predicate,binary predicate)
find_if
find_if_not
find_end finds the last sequence of elements in a range. obj 6(first ,last ,s_first ,s_last, ppolicy ,binary predicate)
find_first_of searches for any one of a set of elements.
adjacent_find finds first two adjacent items that are equal.
search searches for a range of elements.
search_n searches a range for a number of consecutive copies of an element
copy }copies a range of elements to a new location
copy_if
copy_n copies a range of elements to a new location.
copy_backward copies a range of elements in backward order.
move moves a range of elements to a new location.
move_backward moves a range of elements to a new location in backward location.
fill copy-assigns the given value to every element in a range.
fill_n copy-assigns the given value to N elements in a range.
transform applies a function to a range of elements, storing results in a destination range.
generate assigns the results of successive function calls to every element in a range .
generate_n assigns the results of successive function calls to N elements in a range.
remove }removes elements satisfying specific criteria.
remove_if
remove_copy }copies a range of elements omitting those that satisfy specific criteria.
remove_copy_if
replace }replaces all values satisfying specific criteria with another value.
replace_if
replace_copy }copies a range, replacing elements satisfying specific criteria with another value.
replace_copy_if
swap swaps the values of two objects.
swap_ranges swaps two ranges of elements.
iter_swap swaps the elements pointed to by two iterators.
reverse reverses the order of elements in a range.
reverse_copy creates a copy of a range that is reversed.
rotate rotates the order of elements in a range.
rotate_copy copies and rotate a range of elements.
shift_left }shifts elements in a range.
shift_right
shuffle }randomly re-orders elements in a range.
random_shuffle
sample selects n random elements from a sequence.
unique removes consecutive duplicate elements in a range.
unique_copy creates a copy of some range of elements that contains no consecutive duplicates.
is_partitioned determines if the range is partitioned by the given predicate.
partition divides a range of elements into two groups.
partition_copy copies a range dividing the elements into two groups.
stable_partition divides elements into two groups while preserving their relative order.
partition_point locates the partition point of a partitioned range.
is_sorted }checks whether a range is sorted into ascending order.
is_sorted_until
sort sorts a range into ascending order.
partial_sort sorts the first N elements of a range.
partial_sirt_copy copies and partially sorts a range of elements.
stable_sort sorts a range of elements while preserving order between equal elements.
nth_element partially sorts the given range, partitioned by the given element.
lower_bound returns an iterator to the first element not less than the given value.
upper_bound returns an iterator to the first element greater than a certain value.
binary_search determines if an element exists in a certain range.
equal_range returns range of elements matching a specific key.
merge merges two sorted ranges.
inplace_merge merges two ordered ranges in-place.
includes returns true if one sequence is a subsequence of another .
set_differences computes the difference between two sets.
set_interactions computes the intersection of two sets.
set_symmetric_difference computes the symmetric difference between two sets.
set_union computes the union of two sets.
is_heap checks if the given range is a max heap.
is_heap_until finds the largest subrange that is a max heap.
make_heap creates a max heap out of a range of elements.
push_heap adds an element to a max heap.
pop_heap removes the largest element from a max heap.
sort_heap turns a max heap into a range of elements sorted in ascending order.
max returns the greater of the given values.
max_element returns the largest element in a range.
min returns the smaller of the given values.
min_element returns the smallest element in a range.
minmax returns the smaller and larger of two elements.
minmax_element returns the smallest and the largest elements in a range.
clamp clamps a value between a pair of boundary values.
equal determines if two sets of elements are the same.
lexicographical_compare returns true if one range is lexicographically less than another.
lexicographical_compare_three_way compares two ranges using three-way comparison.
is_permutation determines if a sequence is a permutation of another sequence.
next_permutation generates the next greater lexicographic permutation of a range of elements.
prev_permutation generates the next smaller lexicographic permutation of a range of elements.
range::all of the above functions in algorithm
8) <cmath>
abs
fabs }absolute value of a floating point value.
fabsf
fabsl
fmod
fmodf }remainder of the floating point division operation.
fmodl
remainder
remainderf }signed remainder of the division operation.
remainderl
remquo
remquof }signed remainder as well as the three last bits of the division operation.
remquol
fma
fmaf }fused multiply-add operation.
fmal
fmax
fmaxf }larger of two floating point values.
fmaxl
fmin
fminf }smaller of two floating point values.
fminl
fdim
fdimf }positive difference of two floating point values.
fdiml
nan
nanf }not-a-number (NaN).
nanl
lerp linear interpolation function.
exp expf expl returns e raised to the given power.
exp2 exp2f exp2l returns 2 raised to the given power.
expm1 expm1f expm1l returns e raised to the given power, minus one.
log logf logl computes natural (base e) logarithm.
log10 log10f log10l computes common (base 10) logarithm.
log2 log2f log2l base 2 logarithm of the given number.
log1p log1pf log1pl natural logarithm (to base e) of 1 plus the given number.
pow powf powl raises a number to the given power.
sqrt sqrtf sqrtl computes square root.
cbrt cbrtf cbrtl computes cubic root.
hypot hypotf hypotl computes square root of the sum of the squares of two or three given numbers.
sin sinf sinl computes sine.
cos cosf cosl computes cosine.
tan tanf tanl computes tangent.
asin asinf asinl computes arc sine.
acos acosf acosl computes arc cosine.
atan atanf atanl computes arc tangent.
sinh sinhf sinhl computes hyperbolic sine.
cosh coshf coshl computes hyperbolic cosine.
tanh tanhf tanhl computes hyperbolic tangent.
asinh asinhf asinhl computes the inverse hyperbolic sine.
acosh acochf acoshl computes the inverse hyperbolic cosine.
atanh atanhf atanhl computes the inverse hyperbolic tangent.
erf erff erfl error function.
erfc erfcf erfcl complementary error function.
tgamma tgammaf tgammal gamma function.
lgamma lgammaf lgammal natural logarithm of the gamma function.
ceil ceilf ceill nearest integer not less than the given value.
floor floorf floorl nearest integer not greater than the given value.
trunc truncf truncl nearest integer not greater in magnitude than the given value.
round roundf roundl
lround lroundf lroundl } nearest integer, rounding away from zero in halfway cases..
llround llroundf llroundl
nearbyint nearbyintf nearbyintl nearest integer using current rounding mode.
9) <complex>
operator+
operator- }applies unary operators to complex numbers.
opeartor* performs complex number arithmetics on two complex values or a complex and a scalar.
operator/
operator==
operator!= }compares two complex numbers or a complex and a scalar.
operator>>
opeartor<< }serializes and deserializes a complex number.
real returns the real component.
imag returns the imaginary component.
abs returns the magnitude of a complex number.
arg returns the phase angle.
norm returns the squared magnitude.
conj returns the complex conjugate.
proj returns the projection onto the Riemann sphere.
polar constructs a complex number from magnitude and phase angle.
exp complex base e exponential.
log complex natural logarithm with the branch cuts along the negative real axis.
log10 complex common logarithm with the branch cuts along the negative real axis.
pow complex power, one or both arguments may be a complex number.
sqrt complex square root in the range of the right half-plane.
sin cos tan computes sine, cosine and tangent respectively of a complex number.
asin acos atan computes arc sine, arc cosine and arc tangent respectively of a complex number.
sinh cosh tanh computes hyperbolic sine, hyperbolic cosine and hyperbolic tangent respectively of a complex number.
asinh acosh atanh computes area hyperbolic sine, area hyperbolic cosine and area hyperbolic tangent respectively of a complex number.
operator""if
operator""i } A std::complex literal representing pure imaginary number.
operator""il
+6 -6
View File
@@ -524,14 +524,14 @@ Cyan='\033[0;36m' # Cyan
White='\033[0;97m' # White White='\033[0;97m' # White
# Additional colors # Additional colors
LGrey='\033[0;37m' # Light Gray LGrey='\033[0;37m' # Ligth Gray
DGrey='\033[0;90m' # Dark Gray DGrey='\033[0;90m' # Dark Gray
LRed='\033[0;91m' # Light Red LRed='\033[0;91m' # Ligth Red
LGreen='\033[0;92m' # Light Green LGreen='\033[0;92m' # Ligth Green
LYellow='\033[0;93m'# Light Yellow LYellow='\033[0;93m'# Ligth Yellow
LBlue='\033[0;94m' # Light Blue LBlue='\033[0;94m' # Ligth Blue
LPurple='\033[0;95m'# Light Purple LPurple='\033[0;95m'# Light Purple
LCyan='\033[0;96m' # Light Cyan LCyan='\033[0;96m' # Ligth Cyan
# Bold # Bold
+4 -4
View File
@@ -397,8 +397,8 @@ d, t := doubleAndTriple(5)
_, t := doubleAndTriple(3) _, t := doubleAndTriple(3)
// t = 9 // t = 9
// Functions can defer commands. Deferred commands are // Functions can defer commands. Defered commands are
// ran in a stack order after the execution and // runned in a stack order after the execution and
// returning of a function // returning of a function
var aux = 0 var aux = 0
@@ -488,7 +488,7 @@ person3.Age // 0
## Maps ## Maps
Maps are data structures that holds values assigned to a key. Maps are data structures that holds values assigneds to a key.
```go ```go
// Declaring a map // Declaring a map
@@ -508,7 +508,7 @@ newYork // "EUA"
// Delete // Delete
delete(cities, "NY") delete(cities, "NY")
// Check if a key is set // Check if a key is setted
value, ok := cities["NY"] value, ok := cities["NY"]
ok // false ok // false
value // "" value // ""
+1 -1
View File
@@ -308,7 +308,7 @@ for(dataType item : array) {
//Declare a variable, object name //Declare a variable, object name
String s; String s;
//Invoke a constructor to create an object //Invoke a contructor to create an object
s = new String ("Hello World"); s = new String ("Hello World");
//Invoke an instance method that operates on the object's value //Invoke an instance method that operates on the object's value
-6
View File
@@ -95,9 +95,3 @@ arr.reduce(callback[, initialValue]) // Apply a function against
arr.reduceRight(callback[, initialValue]) // Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value. arr.reduceRight(callback[, initialValue]) // Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value.
arr.some(callback[, initialValue]) // Returns true if at least one element in this array satisfies the provided testing function. arr.some(callback[, initialValue]) // Returns true if at least one element in this array satisfies the provided testing function.
arr.values() // Returns a new Array Iterator object that contains the values for each index in the array. arr.values() // Returns a new Array Iterator object that contains the values for each index in the array.
// String methods
String.charAt(index) // Returns the character at the specified index in a string.
String.indexOf(character) // Returns the index of the first occurrence of a specified value in a string.
String.substring(starting_index, ending_index) // Returns a new string that is a subset of the original string.
String.substring(starting_index) // Returns a substring from starting index to last index of string.
+4 -4
View File
@@ -1,8 +1,8 @@
<?php <?php
// Exit the file, string inside get's echo'ed // Exit the file, string inside get's echo'ed
die("This file is not meant to be ran. ¯\_(ツ)_/¯"); die("This file is not ment to be ran. ¯\_(ツ)_/¯");
exit("This file is not meant to be ran. ¯\_(ツ)_/¯"); exit("This file is not ment to be ran. ¯\_(ツ)_/¯");
/** /**
* Printing * Printing
@@ -17,7 +17,7 @@ var_dump($arr); // Print anything, with type hints for any value and sizes
$string = 'Awesome cheatsheets'; $string = 'Awesome cheatsheets';
str_contains($string, 'cheat'); // Find if the string contains the specified string (PHP >= 8.0) str_contains($string, 'cheat'); // Find if the string contains the specified string (PHP >= 8.0)
str_replace('Awesome', 'Bonjour', $string); // Replace all occurrence str_replace('Awesome', 'Bonjour', $string); // Replace all occurence
strcmp($string, 'Awesome cheatsheets'); // Compare two strings strcmp($string, 'Awesome cheatsheets'); // Compare two strings
strpos($string, 'a', 0); // Get position in the string strpos($string, 'a', 0); // Get position in the string
str_split($string, 2); // Split the string str_split($string, 2); // Split the string
@@ -541,7 +541,7 @@ u Pattern is treated as UTF-8
\w Any "word" character (a-z 0-9 _) \w Any "word" character (a-z 0-9 _)
\W Any non "word" character \W Any non "word" character
\s Whitespace (space, tab CRLF) \s Whitespace (space, tab CRLF)
\S Any non whitespace character \S Any non whitepsace character
\d Digits (0-9) \d Digits (0-9)
\D Any non digit character \D Any non digit character
. (Period) - Any character except newline . (Period) - Any character except newline
+1 -1
View File
@@ -71,7 +71,7 @@
| import | import libraries/modules/packages | import | | import | import libraries/modules/packages | import |
| from | import specific function/classes from modules/packages | import | | from | import specific function/classes from modules/packages | import |
| try | this block will be tried to get executed | exception handling | | try | this block will be tried to get executed | exception handling |
| except | is any exception/error has occurred it'll be executed | exception handling | | except | is any exception/error has occured it'll be executed | exception handling |
| finally | It'll be executed no matter exception occurs or not | exception handling | | finally | It'll be executed no matter exception occurs or not | exception handling |
| raise | throws any specific error/exception | exception handling | | raise | throws any specific error/exception | exception handling |
| assert | throws an AssertionError if condition is false | exception handling | | assert | throws an AssertionError if condition is false | exception handling |
-815
View File
@@ -1,815 +0,0 @@
# TypeScript
* TypeScript is a statically typed superset of JavaScript that compiles to plain JavaScript
* It adds optional static type definitions to JavaScript, enabling better tooling and error detection
* In TypeScript, types are checked at compile-time, not runtime
* A TypeScript file has an extension of .ts (or .tsx for React components)
* TypeScript follows JavaScript syntax but adds type annotations and advanced features
* We can compile and run a TypeScript file by the following commands:
`$ tsc filename.ts` (compile to JavaScript)
`$ node filename.js` (run the compiled JavaScript)
Or directly: `$ ts-node filename.ts`
#### TypeScript requires compilation to JavaScript before execution.
## Create and execute a program
1. Install TypeScript globally: `npm install -g typescript`
1. Create the program: `touch program.ts`
1. Write the TypeScript code and save it
1. Compile: `tsc program.ts`
1. Run: `node program.js`
<br>
### Basic Data Types
| Data Type | Description | Example |
| --------- | ----------- | ------- |
| number | Integer and floating point values | `42`, `3.14`, `-7` |
| string | Text values | `"hello"`, `'world'`, `` `template` `` |
| boolean | True/false values | `true`, `false` |
| undefined | Undefined value | `undefined` |
| null | Null value | `null` |
| any | Any type (disables type checking) | Can be anything |
| unknown | Type-safe counterpart of any | Requires type checking |
| void | Absence of any type | Function return type |
| never | Type that never occurs | Functions that throw errors |
| object | Non-primitive types | `{}`, `[]`, functions |
<br>
## Keywords and Reserved Words
<br>
- TypeScript includes all JavaScript keywords plus additional TypeScript-specific ones
| Keyword | Description | Category |
|---------- | ---------- | --------- |
| let | Declares a block-scoped variable | Variable Declaration |
| const | Declares a block-scoped constant | Variable Declaration |
| var | Declares a function-scoped variable | Variable Declaration |
| function | Declares a function | Function |
| class | Declares a class | Class |
| interface | Declares an interface | Type Definition |
| type | Declares a type alias | Type Definition |
| enum | Declares an enumeration | Type Definition |
| namespace | Declares a namespace | Module System |
| module | Declares a module | Module System |
| import | Imports from another module | Module System |
| export | Exports from current module | Module System |
| extends | Class/interface inheritance | Inheritance |
| implements | Class implements interface | Inheritance |
| public | Public access modifier | Access Modifier |
| private | Private access modifier | Access Modifier |
| protected | Protected access modifier | Access Modifier |
| readonly | Read-only property | Access Modifier |
| static | Static class member | Class Member |
| abstract | Abstract class/method | Class |
| async | Asynchronous function | Async Programming |
| await | Awaits a promise | Async Programming |
| new | Creates new instance | Object Creation |
| this | Current object reference | Object Reference |
| super | Parent class reference | Inheritance |
| typeof | Gets type of variable | Type Operation |
| keyof | Gets keys of type | Type Operation |
| in | Property existence check | Type Guard |
| instanceof | Instance type check | Type Guard |
| as | Type assertion | Type Assertion |
| is | Type predicate | Type Guard |
| infer | Infers type in conditional types | Advanced Types |
| declare | Ambient declarations | Declaration |
| get | Property getter | Accessor |
| set | Property setter | Accessor |
| yield | Generator yield | Generator |
<br>
## Operators
<br>
| Operator | Description |
|-|-|
| ( ) | Grouping, function call, type assertion |
| [ ] | Array indexing, array/tuple types |
| . | Property access |
| ?. | Optional chaining |
| ! | Non-null assertion, logical not |
| ~ | Bitwise not |
| \- | Unary minus, arithmetic subtraction |
| \+ | Unary plus, arithmetic addition |
| \* | Multiplication |
| / | Division |
| % | Modulo |
| \*\* | Exponentiation |
| << | Left shift |
| \>> | Right shift |
| \>>> | Unsigned right shift |
| < | Less than |
| <= | Less than or equal |
| \> | Greater than |
| \>= | Greater than or equal |
| == | Equality (with coercion) |
| === | Strict equality |
| != | Inequality (with coercion) |
| !== | Strict inequality |
| & | Bitwise AND |
| ^ | Bitwise XOR |
| \| | Bitwise OR, Union types |
| && | Logical AND |
| \|\| | Logical OR |
| ?? | Nullish coalescing |
| ? : | Ternary conditional |
| = | Assignment |
| += | Add and assign |
| -= | Subtract and assign |
| *= | Multiply and assign |
| /= | Divide and assign |
| %= | Modulo and assign |
| **= | Exponentiate and assign |
| <<= | Left shift and assign |
| \>>= | Right shift and assign |
| &= | Bitwise AND and assign |
| ^= | Bitwise XOR and assign |
| \|= | Bitwise OR and assign |
| , | Comma operator |
| => | Arrow function |
| ... | Spread/rest operator |
### Basic Data Structures
### Array
- Array is an ordered collection of elements of the same or different types.
- Arrays are created using square brackets or Array constructor:
```typescript
let numbers: number[] = [1, 2, 3, 4];
let fruits: Array<string> = ["apple", "banana", "cherry"];
let mixed: (string | number)[] = [1, "two", 3];
```
- Array elements are indexed starting from 0.
- Arrays are mutable - you can change, add, and remove elements.
- Common array methods:
```typescript
let arr = [1, 2, 3];
arr.push(4); // Add to end: [1, 2, 3, 4]
arr.pop(); // Remove from end: [1, 2, 3]
arr.unshift(0); // Add to start: [0, 1, 2, 3]
arr.shift(); // Remove from start: [1, 2, 3]
arr.length; // Get length: 3
```
### Tuple
- Tuple is an array with a fixed number of elements of specific types.
- Tuples are created using square brackets with type annotations:
```typescript
let person: [string, number] = ["John", 30];
let coordinate: [number, number] = [10, 20];
```
- Tuple elements are ordered and have specific types at each position.
- You can access elements by index, but type checking ensures correctness:
```typescript
let point: [number, number] = [10, 20];
console.log(point[0]); // 10 (number)
console.log(point[1]); // 20 (number)
```
- Named tuples provide better readability:
```typescript
let user: [name: string, age: number] = ["Alice", 25];
```
- Optional and rest elements in tuples:
```typescript
let optional: [string, number?] = ["hello"];
let rest: [string, ...number[]] = ["coords", 1, 2, 3];
```
### Set
- Set is a collection of unique values of any type.
- Sets are created using the Set constructor:
```typescript
let uniqueNumbers = new Set<number>([1, 2, 3, 2]); // {1, 2, 3}
let stringSet = new Set<string>();
```
- Set operations:
```typescript
let mySet = new Set<string>();
mySet.add("apple"); // Add element
mySet.has("apple"); // Check existence: true
mySet.delete("apple"); // Remove element
mySet.clear(); // Remove all elements
mySet.size; // Get size
```
- Iterating over Set:
```typescript
let fruits = new Set(["apple", "banana", "cherry"]);
for (let fruit of fruits) {
console.log(fruit);
}
```
### Map
- Map is a collection of key-value pairs where keys can be any type.
- Maps are created using the Map constructor:
```typescript
let userMap = new Map<string, number>();
let mixedMap = new Map<string | number, any>();
```
- Map operations:
```typescript
let map = new Map<string, number>();
map.set("age", 30); // Add key-value pair
map.get("age"); // Get value: 30
map.has("age"); // Check key exists: true
map.delete("age"); // Remove key-value pair
map.clear(); // Remove all entries
map.size; // Get size
```
- Object vs Map:
```typescript
// Object - string/symbol keys only
let obj: { [key: string]: number } = { "age": 30 };
// Map - any type keys
let map = new Map<any, number>();
map.set("age", 30);
map.set(42, 100);
map.set(true, 1);
```
### Object Types and Interfaces
- Objects store key-value pairs and are fundamental to TypeScript.
- Object type annotation:
```typescript
let person: { name: string; age: number } = {
name: "John",
age: 30
};
```
- Interface definition for better reusability:
```typescript
interface User {
readonly id: number; // Read-only property
name: string;
age?: number; // Optional property
[key: string]: any; // Index signature
}
let user: User = {
id: 1,
name: "Alice"
};
```
- Nested objects and complex types:
```typescript
interface Address {
street: string;
city: string;
country: string;
}
interface Person {
name: string;
address: Address;
hobbies: string[];
}
```
### Conditional branching
```typescript
// If-else statements
if (condition) {
// code block
} else if (anotherCondition) {
// code block
} else {
// code block
}
// Ternary operator
let result = condition ? valueIfTrue : valueIfFalse;
// Switch statement
switch (variable) {
case value1:
// code
break;
case value2:
// code
break;
default:
// code
break;
}
```
### Loops
TypeScript supports all JavaScript loop constructs:
#### For loop
```typescript
// Traditional for loop
for (let i = 0; i < 5; i++) {
console.log(i);
}
// For-of loop (iterates over values)
let fruits = ["apple", "banana", "cherry"];
for (let fruit of fruits) {
console.log(fruit);
}
// For-in loop (iterates over keys/indices)
for (let index in fruits) {
console.log(index, fruits[index]);
}
```
#### While loop
```typescript
let i = 0;
while (i < 5) {
console.log(i);
i++;
}
// Do-while loop
let j = 0;
do {
console.log(j);
j++;
} while (j < 5);
```
#### Loop control
```typescript
for (let i = 0; i < 10; i++) {
if (i === 3) continue; // Skip iteration
if (i === 7) break; // Exit loop
console.log(i);
}
```
### Function definition
```typescript
// Function declaration
function functionName(param1: type, param2: type): returnType {
return value;
}
// Function expression
const functionName = function(param: type): returnType {
return value;
};
// Arrow function
const functionName = (param: type): returnType => {
return value;
};
// Arrow function (concise)
const functionName = (param: type): returnType => value;
```
### Function variations
```typescript
// Optional parameters
function greet(name: string, age?: number): string {
return age ? `Hello ${name}, you are ${age}` : `Hello ${name}`;
}
// Default parameters
function multiply(a: number, b: number = 1): number {
return a * b;
}
// Rest parameters
function sum(...numbers: number[]): number {
return numbers.reduce((total, num) => total + num, 0);
}
// Function overloads
function process(input: string): string;
function process(input: number): number;
function process(input: string | number): string | number {
if (typeof input === 'string') {
return input.toUpperCase();
}
return input * 2;
}
// Generic functions
function identity<T>(arg: T): T {
return arg;
}
let result = identity<string>("hello"); // Type is string
let result2 = identity(42); // Type inferred as number
```
### Function call
```typescript
functionName(argument1, argument2);
// With optional parameters
greet("John"); // "Hello John"
greet("John", 25); // "Hello John, you are 25"
// With rest parameters
sum(1, 2, 3, 4); // 10
// Generic function call
identity<string>("hello");
identity(42); // Type inferred
```
### Classes
```typescript
class ClassName {
// Properties
public publicProperty: type;
private privateProperty: type;
protected protectedProperty: type;
readonly readonlyProperty: type;
static staticProperty: type;
// Constructor
constructor(param: type) {
this.publicProperty = param;
}
// Methods
public method(): returnType {
return value;
}
// Getters and setters
get property(): type {
return this.privateProperty;
}
set property(value: type) {
this.privateProperty = value;
}
// Static method
static staticMethod(): returnType {
return value;
}
}
// Inheritance
class ChildClass extends ParentClass {
constructor(param: type) {
super(param); // Call parent constructor
}
// Override method
method(): returnType {
return super.method(); // Call parent method
}
}
// Abstract class
abstract class AbstractClass {
abstract abstractMethod(): void;
concreteMethod(): void {
console.log("This is implemented");
}
}
```
### Key TypeScript Features
* **Static Typing**: Types are checked at compile-time
* **Type Inference**: TypeScript can often infer types automatically
* **Optional Typing**: You can gradually add types to existing JavaScript
* **Generics**: Create reusable components that work with multiple types
* **Interfaces**: Define contracts for objects and classes
* **Enums**: Create named constants
* **Union Types**: Variables can be one of several types
* **Intersection Types**: Combine multiple types
* **Type Guards**: Runtime type checking
* **Decorators**: Add metadata to classes and methods
### Compilation
* TypeScript code must be compiled to JavaScript before execution
* The TypeScript compiler (`tsc`) performs type checking and transpilation
* Configuration is managed through `tsconfig.json`
* TypeScript can target different JavaScript versions (ES5, ES6, etc.)
* Source maps can be generated for debugging compiled code
#### Sample TypeScript Code
**hello.ts**
```typescript
// TypeScript source code
interface User {
name: string;
age: number;
isActive?: boolean;
}
class UserManager {
private users: User[] = [];
addUser(user: User): void {
this.users.push(user);
console.log(`Added user: ${user.name}`);
}
getActiveUsers(): User[] {
return this.users.filter(user => user.isActive ?? true);
}
getUserCount(): number {
return this.users.length;
}
}
// Generic function
function processData<T>(data: T[], processor: (item: T) => T): T[] {
return data.map(processor);
}
// Usage
const userManager = new UserManager();
const newUser: User = {
name: "John Doe",
age: 30,
isActive: true
};
userManager.addUser(newUser);
// Arrow functions with types
const formatUser = (user: User): string =>
`${user.name} (${user.age} years old)`;
// Union types and type guards
function displayInfo(value: string | number | boolean): string {
if (typeof value === "string") {
return `Text: ${value.toUpperCase()}`;
} else if (typeof value === "number") {
return `Number: ${value.toFixed(2)}`;
} else {
return `Boolean: ${value ? "Yes" : "No"}`;
}
}
console.log(displayInfo("hello"));
console.log(displayInfo(42.567));
console.log(displayInfo(true));
```
#### Compilation Commands
```bash
# Compile single file
tsc hello.ts
# Compile with specific target
tsc hello.ts --target ES2020
# Compile with source maps
tsc hello.ts --sourceMap
# Watch mode (recompile on changes)
tsc hello.ts --watch
# Compile all files in project
tsc
# Check for errors without generating files
tsc --noEmit
# Compile with strict mode
tsc hello.ts --strict
```
#### Compiled JavaScript Output
**hello.js** (compiled from above TypeScript)
```javascript
"use strict";
// JavaScript output (target ES2017)
class UserManager {
constructor() {
this.users = [];
}
addUser(user) {
this.users.push(user);
console.log(`Added user: ${user.name}`);
}
getActiveUsers() {
return this.users.filter(user => user.isActive ?? true);
}
getUserCount() {
return this.users.length;
}
}
// Generic function (types removed)
function processData(data, processor) {
return data.map(processor);
}
// Usage
const userManager = new UserManager();
const newUser = {
name: "John Doe",
age: 30,
isActive: true
};
userManager.addUser(newUser);
// Arrow functions
const formatUser = (user) => `${user.name} (${user.age} years old)`;
// Type guards remain as runtime checks
function displayInfo(value) {
if (typeof value === "string") {
return `Text: ${value.toUpperCase()}`;
}
else if (typeof value === "number") {
return `Number: ${value.toFixed(2)}`;
}
else {
return `Boolean: ${value ? "Yes" : "No"}`;
}
}
console.log(displayInfo("hello"));
console.log(displayInfo(42.567));
console.log(displayInfo(true));
```
#### tsconfig.json Configuration
```json
{
"compilerOptions": {
// Basic Options
"target": "ES2020", // Target JavaScript version
"module": "commonjs", // Module system
"lib": ["ES2020", "DOM"], // Include library files
"outDir": "./dist", // Output directory
"rootDir": "./src", // Input directory
"strict": true, // Enable strict type checking
// Additional Checks
"noUnusedLocals": true, // Error on unused variables
"noUnusedParameters": true, // Error on unused parameters
"noImplicitReturns": true, // Error on missing return statements
"noFallthroughCasesInSwitch": true, // Error on fallthrough cases
// Module Resolution
"moduleResolution": "node", // Module resolution strategy
"baseUrl": "./", // Base directory
"paths": { // Path mapping
"@/*": ["src/*"],
"@utils/*": ["src/utils/*"]
},
// Source Maps & Debugging
"sourceMap": true, // Generate source maps
"inlineSourceMap": false, // Don't inline source maps
"declaration": true, // Generate .d.ts files
"declarationMap": true, // Generate .d.ts.map files
// Experimental
"experimentalDecorators": true, // Enable decorators
"emitDecoratorMetadata": true, // Emit decorator metadata
// JavaScript Support
"allowJs": true, // Allow JavaScript files
"checkJs": false, // Type check JavaScript files
// Other Options
"esModuleInterop": true, // CommonJS/ES6 interop
"skipLibCheck": true, // Skip lib.d.ts type checking
"forceConsistentCasingInFileNames": true, // Consistent file names
"removeComments": true, // Remove comments from output
"noEmitOnError": true // Don't emit if there are errors
},
"include": [
"src/**/*", // Include all files in src
"tests/**/*" // Include test files
],
"exclude": [
"node_modules", // Exclude node_modules
"dist", // Exclude output directory
"**/*.test.ts", // Exclude test files from compilation
"**/*.spec.ts"
],
"files": [
// Explicitly include specific files (optional)
"src/main.ts"
]
}
```
#### Package.json Scripts
```json
{
"name": "typescript-project",
"version": "1.0.0",
"scripts": {
"build": "tsc",
"start": "node dist/main.js",
"dev": "ts-node src/main.ts",
"watch": "tsc --watch",
"clean": "rm -rf dist",
"type-check": "tsc --noEmit"
},
"devDependencies": {
"typescript": "^4.9.0",
"ts-node": "^10.9.0",
"@types/node": "^18.0.0"
}
}
```
#### Compilation Examples with Different Targets
**Original TypeScript:**
```typescript
const greet = (name: string = "World"): string => `Hello, ${name}!`;
const user = { name: "Alice", age: 30 };
const { name, age } = user;
```
**Compiled to ES5:**
```javascript
var greet = function (name) {
if (name === void 0) { name = "World"; }
return "Hello, " + name + "!";
};
var user = { name: "Alice", age: 30 };
var name = user.name, age = user.age;
```
**Compiled to ES2020:**
```javascript
const greet = (name = "World") => `Hello, ${name}!`;
const user = { name: "Alice", age: 30 };
const { name, age } = user;
```
#### Error Examples
**TypeScript with errors:**
```typescript
// Type errors that prevent compilation
let message: string = 42; // Error: Type 'number' is not assignable to type 'string'
let numbers: number[] = ["a", "b"]; // Error: Type 'string' is not assignable to type 'number'
function add(a: number, b: number): number {
return a + b;
}
add("hello", "world"); // Error: Argument of type 'string' is not assignable to parameter of type 'number'
```
**Compiler output:**
```bash
$ tsc error-example.ts
error-example.ts(2,5): error TS2322: Type 'number' is not assignable to type 'string'.
error-example.ts(3,5): error TS2322: Type 'string[]' is not assignable to type 'number[]'.
error-example.ts(8,5): error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
```
-1
View File
@@ -21,7 +21,6 @@ cat /proc/<process_id>/maps # Show the current virtual memory usage of a Linux
ip r # Display ip of the server ip r # Display ip of the server
lsof -i :9000 # List process running on port 9000 lsof -i :9000 # List process running on port 9000
kill -9 $(lsof -t -i:PORT) # Kill the process running on whichever port specified
journalctl -u minio.service -n 100 --no-pager # List last 100 logs for specific service journalctl -u minio.service -n 100 --no-pager # List last 100 logs for specific service
+20 -75
View File
@@ -20,15 +20,13 @@ e jump to end of words (punctuation considered words)
E jump to end of words (no punctuation) E jump to end of words (no punctuation)
b jump backward by words (punctuation considered words) b jump backward by words (punctuation considered words)
B jump backward by words (no punctuation) B jump backward by words (no punctuation)
ge jump backward to end of a word ge jump backward to end of words
gE jump backwards to the end of a word (words can contain punctuation)
0 (zero) start of line 0 (zero) start of line
^ first non-blank character of line ^ first non-blank character of line
$ jump to the end of the line $ end of line
g_ jump to the last non-blank character of the line - move line upwards, on the first non blank character
- move line upwards, on the first non-blank character + move line downwards, on the first non blank character
+ move line downwards, on the first non-blank character <enter> move line downwards, on the first non blank character
<enter> move line downwards, on the first non-blank character
gg go to first line gg go to first line
G go to last line G go to last line
ngg go to line n ngg go to line n
@@ -40,6 +38,10 @@ nG go To line n
} move the cursor a paragraph forwards } move the cursor a paragraph forwards
]] move the cursor a section forwards or to the next { ]] move the cursor a section forwards or to the next {
[[ move the cursor a section backwards or the previous { [[ move the cursor a section backwards or the previous {
CTRL-f move the cursor forward by a screen of text
CTRL-b move the cursor backward by a screen of text
CTRL-u move the cursor up by half a screen
CTRL-d move the cursor down by half a screen
H move the cursor to the top of the screen. H move the cursor to the top of the screen.
M move the cursor to the middle of the screen. M move the cursor to the middle of the screen.
L move the cursor to the bottom of the screen. L move the cursor to the bottom of the screen.
@@ -47,16 +49,6 @@ fx search line forward for 'x'
Fx search line backward for 'x' Fx search line backward for 'x'
tx search line forward before 'x' tx search line forward before 'x'
Tx search line backward before 'x' Tx search line backward before 'x'
CTRL-y moves screen up one line
CTRL-e moves screen down one line
CTRL-u moves cursor & screen up ½ page
CTRL-d moves cursor & screen down ½ page
CTRL-b moves screen up one page, cursor to last line
CTRL-f moves screen down one page, cursor to first line
zz shift current line to middle of screen
z. same as zz but also jumps to the first non-black character
zt shift current line to top of screen
zb shift current line to bottom of screen
############################################################################## ##############################################################################
@@ -68,15 +60,8 @@ zb shift current line to bottom of screen
ma make a bookmark named a at the current cursor position ma make a bookmark named a at the current cursor position
`a go to position of bookmark a `a go to position of bookmark a
'a go to the line with bookmark a 'a go to the line with bookmark a
`0 go to the position where Vim was previously exited
`" go to the position when last editing this file
`. go to the line that you last edited `. go to the line that you last edited
`` go to the position before the last jump
g, go to newer position in change list
g; go to older position in change list
# Tip: To jump to a mark you can either use a backtick (`) or an apostrophe (').
# Using an apostrophe jumps to the beginning (first non-blank) of the line holding the mark.
############################################################################## ##############################################################################
# INSERT MODE # INSERT MODE
@@ -85,13 +70,10 @@ g; go to older position in change list
i start insert mode at cursor i start insert mode at cursor
I insert at the beginning of the line I insert at the beginning of the line
gi return to insert mode where you inserted text the last time
gI like "I", but always start in column 1
a append after the cursor a append after the cursor
A append at the end of the line A append at the end of the line
o open (append) blank line below current line o open (append) blank line below current line
O open blank line above current line O open blank line above current line
CTRL-o Temporarily enter normal mode to issue one normal-mode command(while in insert mode)
Esc exit insert mode Esc exit insert mode
@@ -102,25 +84,10 @@ Esc exit insert mode
r replace a single character (does not use insert mode) r replace a single character (does not use insert mode)
R enter Insert mode, replacing characters rather than inserting R enter Insert mode, replacing characters rather than inserting
J join line below to the current one with one space in between J join line below to the current one
gJ join line below to the current one without space in between
cc change (replace) an entire line cc change (replace) an entire line
cw change (replace) to the end of word (same as ce) cw change (replace) to the end of word
2cw change (replace) repeat cw twice C change (replace) to the end of line
ciw change (replace) word under the cursor
caw change (replace) word under the cursor and the space after or before it
ci" change (replace) word inside ""
cit change (replace) html tag content
cat change (replace) html tag
cis change (replace) sentence under the cursor
cas change (replace) sentence under the cursor and the space after or before it
cib change (replace) inside a block with ()
cab change (replace) a block with ()
ciB change (replace) inside a block with {}
caB change (replace) a block with {}
C change (replace) to the end of line(same as c$)
cG change (replace) to the end of the file
cgg change (replace) from first line to current line
ct' change (replace) until the ' character (can change ' for any character) ct' change (replace) until the ' character (can change ' for any character)
s delete character at cursor and substitute text s delete character at cursor and substitute text
S delete line at cursor and substitute text (same as cc) S delete line at cursor and substitute text (same as cc)
@@ -135,7 +102,6 @@ guiw make current word lowercase
gU$ make uppercase until end of line gU$ make uppercase until end of line
gu$ make lowercase until end of line gu$ make lowercase until end of line
>> indent line one column to right >> indent line one column to right
>i{ indent everything in the {}
<< indent line one column to left << indent line one column to left
== auto-indent current line == auto-indent current line
ddp swap current line with next ddp swap current line with next
@@ -144,7 +110,6 @@ ddkP swap current line with previous
:r [name] insert the file [name] below the cursor. :r [name] insert the file [name] below the cursor.
:r !{cmd} execute {cmd} and insert its standard output below the cursor. :r !{cmd} execute {cmd} and insert its standard output below the cursor.
# Tip: Instead of b or B one can also use ( or { respectively.
############################################################################## ##############################################################################
# DELETING TEXT # DELETING TEXT
@@ -153,15 +118,10 @@ ddkP swap current line with previous
x delete current character x delete current character
X delete previous character X delete previous character
dw delete (cut) to the end of word (same as de) dw delete the current word
diw delete (cut) word under the cursor
daw delete (cut) word under the cursor and the space after or before it
dap delete (cut) a paragraph
dd delete (cut) a line dd delete (cut) a line
dt' delete (cut) until the next ' character on the line (replace ' by any character) dt' delete until the next ' character on the line (replace ' by any character)
dG delete (cut) to the end of the file D delete from cursor to end of line
dgg delete (cut) from first line to current line
D delete (cut) from cursor to end of line (same as d$)
:[range]d delete [range] lines :[range]d delete [range] lines
@@ -176,10 +136,6 @@ yy yank (copy) a line
y$ yank to end of line y$ yank to end of line
p put (paste) the clipboard after cursor/current line p put (paste) the clipboard after cursor/current line
P put (paste) before cursor/current line P put (paste) before cursor/current line
gp put (paste) the clipboard after cursor and leave cursor after the new text
gP put (paste) before cursor and leave cursor after the new text
"+y yank into the system clipboard register
"+p paste from the system clipboard register
:set paste avoid unexpected effects in pasting :set paste avoid unexpected effects in pasting
:registers display the contents of all registers :registers display the contents of all registers
"xyw yank word into register x "xyw yank word into register x
@@ -191,12 +147,6 @@ gP put (paste) before cursor and leave cursor after the new tex
"xgP just like "P", but leave the cursor just after the new text "xgP just like "P", but leave the cursor just after the new text
:[line]put x put the text from register x after [line] :[line]put x put the text from register x after [line]
# Tip: if you are using vim extension on vs code, you can enable
"vim.useSystemClipboard": true
in setting.json, this will allow to Use system clipboard for unnamed register.
############################################################################## ##############################################################################
# MACROS # MACROS
@@ -207,7 +157,6 @@ qa start recording macro 'a'
q end recording macro q end recording macro
@a replay macro 'a' @a replay macro 'a'
@: replay last command @: replay last command
@@ repeat macro
############################################################################## ##############################################################################
@@ -223,11 +172,9 @@ CTRL-v start visual block mode
O move to other corner of block O move to other corner of block
aw mark a word aw mark a word
ab a () block (with braces) ab a () block (with braces)
aB a {} block (with brackets) ab a {} block (with brackets)
at a block with <> tags
ib inner () block ib inner () block
iB inner {} block ib inner {} block
it inner <> block
Esc exit visual mode Esc exit visual mode
VISUAL MODE COMMANDS VISUAL MODE COMMANDS
@@ -247,7 +194,6 @@ v% selects matching parenthesis
vi{ selects matching curly brace vi{ selects matching curly brace
vi" selects text between double quotes vi" selects text between double quotes
vi' selects text between single quotes vi' selects text between single quotes
gv reselect the last selected area
############################################################################## ##############################################################################
# SPELLING # SPELLING
@@ -337,6 +283,7 @@ CTRL-w < increase window width
CTRL-w > decrease window width CTRL-w > decrease window width
CTRL-w = equal window CTRL-w = equal window
CTRL-w o close other windows CTRL-w o close other windows
zz Centers the window to the current line
############################################################################## ##############################################################################
@@ -359,14 +306,12 @@ clast display the last error
% show matching brace, bracket, or parenthese % show matching brace, bracket, or parenthese
gf edit the file whose name is under the cursor gf edit the file whose name is under or after the cursor
gF edit the file whose name is under the cursor and jump to the line number
gd when the cursor is on a local variable or function, jump to its declaration gd when the cursor is on a local variable or function, jump to its declaration
'' return to the line where the cursor was before the latest jump '' return to the line where the cursor was before the latest jump
gi return to insert mode where you inserted text the last time
CTRL-o move to previous position you were at CTRL-o move to previous position you were at
CTRL-i move to more recent position you were at CTRL-i move to more recent position you were at
:set nu display numbers (short for :set number)
:set nonu hide numbers (short for :set nonumber)
############################################################################## ##############################################################################