JavaScript Tutorial (2024) for Beginners to Pro

 

Introduction

JavaScript is one of the most popular programming languages used for web development. Whether you are a beginner or looking to advance your skills, this guide will take you from the basics to advanced concepts with notes, projects, and practice questions.

Table of Contents

1. Introduction to JavaScript

2. JavaScript Basics

3. Functions and Scope

4. Objects and Arrays

5. ES6+ Features

6. DOM Manipulation

7. Events and Event Listeners

8. Asynchronous JavaScript

9. API Integration & Fetch API

10. Projects for Practice

11. Practice Questions

12. Conclusion

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1. Introduction to JavaScript

JavaScript is a scripting language used to create dynamic web pages. It allows developers to build interactive web applications.

Why Learn JavaScript?

• Used for frontend and backend development.

• Supported by all modern browsers.

• Extensive libraries and frameworks (React, Angular, Vue, Node.js).

• High demand in the job market.

2. JavaScript Basics

Variables & Data Types

let name = "John"; // String
const age = 25; // Number
let isStudent = true; // Boolean

Operators

• Arithmetic: +, -, *, /, %

• Comparison: ==, ===, !=, >, <

• Logical: &&, ||, !

3. Functions and Scope

Function Declaration

function greet(name) {
    return `Hello, ${name}!`;
}
console.log(greet("Raees"));

Function Expression & Arrow Functions

const add = (a, b) => a + b;
console.log(add(5, 3));

Scope

• Global Scope: Accessible throughout the script.

• Local Scope: Accessible within a function or block.

4. Objects and Arrays

Objects

let person = {
    name: "Ali",
    age: 30,
    greet: function() {
        return `Hi, I am ${this.name}`;
    }
};
console.log(person.greet());

Arrays

let fruits = ["Apple", "Banana", "Orange"];
console.log(fruits[0]); // Apple

5. ES6+ Features

• let & const (Block Scope Variables)

• Template Literals (`Hello ${name}`)

• Destructuring

• Spread & Rest Operators

• Async/Await

6. DOM Manipulation

Selecting Elements

document.getElementById("myId");
document.querySelector(".myClass");

Modifying Elements

document.getElementById("title").innerText = "New Title";

7. Events and Event Listeners

document.getElementById("btn").addEventListener("click", function() {
    alert("Button Clicked!");
});

8. Asynchronous JavaScript

• Callbacks

• Promises

• Async/Await

async function fetchData() {
    let response = await fetch("https://api.example.com/data");
    let data = await response.json();
    console.log(data);
}
fetchData();

9. API Integration & Fetch API

fetch("https://jsonplaceholder.typicode.com/posts")
    .then(response => response.json())
    .then(data => console.log(data));

10. Projects for Practice

Beginner Projects

1. To-Do List

2. Calculator

3. Digital Clock

Intermediate Projects

4. Weather App (API Integration)

5. Quiz App

6. Expense Tracker

Advanced Projects

7. E-commerce Website (Full-Stack)

8. Chat Application

9. Portfolio Website

11. Practice Questions

1. Write a function to check if a number is even or odd.

2. Create an object representing a car with properties like brand, model, and year.

3. Implement a function that reverses a string.

4. Write a JavaScript program to find the largest number in an array.

5. Create a function that fetches and displays data from an API.

12. Conclusion

By following this guide, you will gain a strong foundation in JavaScript. Keep practicing, building projects, and solving problems to become a pro in JavaScript development.