JavaScript Lesson 1 - Introductionto JavaScript| Dataplexa
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Introduction to JavaScript

JavaScript is the programming language that makes web pages interactive. It allows websites to respond to user actions, update content dynamically, and communicate with servers without reloading the page.

What is JavaScript?

JavaScript is a high-level, interpreted programming language primarily used for building interactive web applications. It runs directly inside web browsers and is supported by all modern browsers.

While HTML defines the structure of a page and CSS controls the design, JavaScript controls the behavior of a website.

  • Handles user interactions like clicks and typing
  • Updates content dynamically
  • Validates forms
  • Communicates with APIs

Why JavaScript is Important

JavaScript is the backbone of modern web development. It is the only programming language that runs natively in all web browsers.

  • Used by almost every website on the internet
  • Essential for Frontend, Backend, and Full-Stack development
  • Works with modern frameworks like React, Angular, and Vue
  • Strong job demand worldwide

Where JavaScript is Used

  • Web Development – Interactive websites and dashboards
  • Backend Development – Using Node.js
  • Mobile Applications – React Native
  • Desktop Applications – Electron
  • Game Development

Your First JavaScript Program

Let’s start with a simple JavaScript statement that prints a message. 


console.log("Hello, JavaScript!");

This line sends text to the browser’s console. You will learn more about the console and debugging tools in upcoming lessons.

JavaScript vs Java

Despite the similar names, JavaScript and Java are completely different programming languages.

  • JavaScript is lightweight and runs in browsers
  • Java is a compiled, class-based language
  • They are used for different purposes

Do not confuse JavaScript with Java.

What You Will Learn in This Course

By the end of this JavaScript course, you will be able to:

  • Write clean and readable JavaScript code
  • Create interactive web pages
  • Work with the DOM
  • Handle asynchronous operations
  • Build real-world projects

What’s Next?

In the next lesson, you will learn how to set up JavaScript properly, choose a code editor, and run JavaScript code in the browser.

Continue to Lesson 2: Setup & Editors

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