Introduction to JavaScript

Here's a simple example that shows how to declare variables, create a function, and output text to the console:

// Declare variables
let greeting = "Hello, World!";
const year = 2025;

// Function to display greeting
function showGreeting() {
  console.log(greeting + " Welcome to JavaScript in " + year);
}

// Call the function
showGreeting();
          

This example demonstrates:

• Variable declaration using let and const
• Function definition and invocation
• String concatenation and console output

• Client-Side Execution: Runs in the user's browser for responsive user experiences.
• Interpreted Language: No compilation needed — code runs directly.
• Event Handling: Reacts to user inputs like clicks and keyboard events.
• Extensive Ecosystem: Vast libraries and frameworks such as React, Angular, and Vue.js.
• Server-Side Usage: With Node.js, JavaScript can power backend services and APIs.

• Web Development: Creating interactive UI elements, form validation, animations.
• Server-Side Programming: Using Node.js to build scalable web servers and APIs.
• Mobile Apps: Frameworks like React Native enable mobile app development.
• Game Development: Browser-based games leveraging Canvas and WebGL.
• Desktop Applications: Electron allows building cross-platform desktop apps.