JavaScript HOME

1. What is JavaScript?

JavaScript (JS) is a lightweight, interpreted programming language with first-class functions, commonly used as a part of web pages, allowing client-side script to interact with the user and make dynamic pages.

2. Features of JavaScript

  • Dynamic Typing: Variables can hold multiple types of values over time.
  • Object-Oriented: Supports objects and offers features like inheritance through prototypes.
  • Functional Programming: Functions are treated as first-class citizens.
  • Event-Driven: Handles events like clicks, inputs, and server responses.

3. How to Run JavaScript

JavaScript can be run in a web browser or on a server using platforms like Node.js.

Running in a Browser:

  1. Inline Script: Directly inside HTML <script> tags. 
    <script>
  alert('Hello, World!');
</script>

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  2. External File: Link an external JavaScript file. 
    <script src="script.js"></script>

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Running on a Server:

  1. Install Node.js.
  2. Create a .js file and run it using the command: 
    node file.js

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4. Basic Example

<!DOCTYPE html>
<html>
<head>
  <title>JavaScript Example</title>
</head>
<body>
  <h1>Welcome to JavaScript</h1>
  <button onclick="sayHello()">Click Me</button>

  <script>
    function sayHello() {
      alert('Hello, JavaScript!');
    }
  </script>
</body>
</html>

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5. Development Environment

  • Text Editors: VS Code, Sublime Text, Atom.
  • Browsers: Google Chrome, Mozilla Firefox (for debugging and testing).

6. Benefits of JavaScript

  • Cross-Platform: Works on any platform with a browser.
  • Rich Interfaces: Enables the creation of interactive web applications.
  • Asynchronous Processing: Supports AJAX, fetching data without reloading the page.

7. Conclusion

JavaScript is essential for modern web development. It enhances user experiences by providing dynamic content and interaction on websites. Starting with basic understanding and practice, you can explore its advanced features like APIs, frameworks, and libraries to build robust web applications.