JavaScript Tutorial Roadmap

Introduction to JavaScript

What is JavaScript?

JavaScript is a high-level, interpreted programming language used to create dynamic, interactive, and responsive web applications. It runs in the browser as well as on servers (using Node.js).

Importance of JavaScript in Web Development

• Core technology of the web (HTML, CSS, JavaScript)
• Enables interactivity and dynamic content
• Used for frontend, backend, mobile apps, and desktop apps
• Supported by all modern browsers

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Basic JavaScript Syntax

Adding JavaScript to HTML

• Inline JavaScript
• Internal scripts
• External JavaScript files

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Variables and Data Types

Variables

• Declaring variables using var, let, and const

Data Types

• Primitive data types (Number, String, Boolean, Undefined, Null, Symbol)
• Reference data types (Object, Array, Function)

Constants

• Declaring immutable values using const

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Operators in JavaScript

Arithmetic Operators

• Addition, subtraction, multiplication, division, modulus

Comparison Operators

• ==, ===, !=, !==, >, <, >=, <=

Logical Operators

• AND (&&), OR (||), NOT (!)

Assignment Operators

• =, +=, -=, *=, /=

Conditional (Ternary) Operator

• Writing concise conditional expressions

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Control Structures

Conditional Statements

• if statement
• if-else statement
• else-if ladder
• switch statement

Loops

• for loop
• while loop
• do-while loop

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Functions in JavaScript

Function Declaration

• Defining reusable functions

Function Expression

• Assigning functions to variables

Arrow Functions

• Shorter function syntax using =>

Callback Functions

• Passing functions as arguments

Higher-Order Functions

• Functions that return or accept other functions

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Objects and Arrays

Objects

• Creating and accessing object properties

Arrays

• Creating arrays
• Accessing and modifying array elements

Array Methods

• map(), filter(), reduce(), forEach()

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DOM Manipulation

Selecting Elements

• getElementById
• querySelector
• querySelectorAll

Modifying Elements

• Changing text, HTML, and styles

Event Handling

• Adding event listeners
• Handling user interactions

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ES6 (ECMAScript 2015) Features

let and const

• Block-scoped variables

Template Literals

• String interpolation using backticks

Destructuring

• Extracting values from arrays and objects

Spread and Rest Operators

• Expanding and collecting values

Modules

• Importing and exporting JavaScript modules

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Asynchronous JavaScript

Callbacks

• Handling asynchronous operations

Promises

• Managing async operations with .then() and .catch()

Async / Await

• Writing asynchronous code in a synchronous style

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Error Handling in JavaScript

try…catch

• Catching runtime errors

Throwing Errors

• Using throw keyword

Custom Errors

• Creating custom error objects

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Advanced JavaScript Topics

Closures

• Functions with preserved lexical scope

this Keyword

• Understanding context in JavaScript

Prototypes and Inheritance

• Prototype chain and object inheritance

Classes

• ES6 class syntax

Modules

• Organizing code using modules

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JavaScript Best Practices

Writing Clean and Maintainable Code

• Naming conventions
• Code readability and structure

Debugging Techniques

• Browser developer tools
• Console debugging

Performance Optimization

• Reducing DOM manipulation
• Optimizing loops and functions