JavaScript Docs
JavaScript is a high-level, versatile scripting language primarily used to create interactive effects within web browsers.
Creator: Brendan Eich Profile
Official Repo Link
Core Concepts & Setup
What is JavaScript
Lightweight, interpreted programming language of the web.
History of JS
Created by Brendan Eich in 1995 at Netscape.
Setup & Environment
Browser console, Node.js, and editors to run JS.
Hello World
Your first JavaScript program and output methods.
Comments
Single-line and multi-line comments in JS.
Strict Mode
Enforce stricter parsing and error handling in JS.
Syntax & Building Blocks
Variables (var/let/const)
Declare & store values using different keywords.
Data Types
Primitive & reference types in JavaScript.
Type Conversion & Coercion
Implicit vs explicit conversion in JS.
Truthy & Falsy Values
How JS evaluates values in boolean context.
Operators
Arithmetic, assignment, comparison, logical & others.
Control Statements
If-else, switch, loops (for, while, do-while).
Loops in JavaScript
for, while, do–while, for…in, for…of.
Functions & Scopes
Functions
Declaration, Expression & Arrow functions in JS.
Scope & Hoisting
Understanding lexical scope and hoisting.
Closures
Functions with preserved lexical environment.
this Keyword
How "this" behaves in different contexts.
Call, Apply, Bind
Explicitly set "this" value in functions.
Default & Rest Parameters
Flexible function arguments handling.
Objects, Arrays & DOM
Objects & Prototypes
JavaScript object creation and inheritance.
Object Methods
Object.keys, Object.values, Object.entries, Object.assign.
Arrays & Methods
Common methods like map, filter, reduce.
Destructuring & Spread
Extract values and use ...spread/rest.
Browser DOM
Interact with HTML elements using JavaScript.
Events
Handle clicks, inputs, submit events etc.
Event Delegation
Efficient event handling strategy.
JSON
JavaScript Object Notation – lightweight data format.
Fetch API
Make HTTP requests in the browser.
Asynchronous JavaScript
Callbacks
First asynchronous technique in JavaScript.
Promises
Handle async operations with .then() & .catch().
Async / Await
Modern way to write asynchronous code.
Event Loop
How JavaScript handles concurrency.
Microtasks vs Macrotasks
Queues and priorities in async execution.
setTimeout & setInterval
Timers and scheduling in JavaScript.
Advanced Concepts
ES6+ Features
Let, const, template literals, destructuring, etc.
Modules
Import/export syntax & modular JS.
Error Handling
try...catch...finally blocks and errors.
OOP in JavaScript
Classes, constructor functions & prototype chains.
Symbols & BigInt
Special data types for unique values & large integers.
Iterators & Generators
Custom iteration logic in JS.
Regular Expressions
Pattern matching and text manipulation.
Debouncing & Throttling
Optimize performance of frequent events.
Memory & Garbage Collection
How JavaScript manages memory under the hood.
Node.js Intro
JavaScript runtime outside the browser.
JavaScript in Web
LocalStorage
Store key-value pairs in browser.
SessionStorage
Temporary storage that clears on tab close.
Cookies
Store small pieces of data with expiration.
IndexedDB
Client-side NoSQL database for complex data.
Geolocation API
Access user location with JS.
Clipboard API
Copy and paste functionality in JS.
Notifications API
Send system notifications from web apps.
Service Workers
Enable offline capabilities (PWA).
WebSockets
Real-time communication in JS.
Security Concepts