webrun

JavaScript Online Compiler & Playground

Your private JavaScript sandbox. Your code stays in your browser and never leaves your device. Learn, test, prototype!

Output:

Output will appear here...

Share and Learn

  • Share securely - Share code using time-sensitive links and optional password protection
  • AI explanations - An AI assistant that explains how the code works, making it easier to learn and understand
  • AI code review - An AI code review assistant that reviews your code for bugs, readability, and potential improvements

About JavaScript

JavaScript is the programming language of the web. It’s a versatile, high-level language that runs in browsers and enables interactive web pages. With modern frameworks, JavaScript is used to build rich, interactive applications.

Why JavaScript?

  • Universal - Runs in every web browser without installation
  • Versatile - Frontend, backend, mobile, and desktop development
  • Rich Ecosystem - npm has the largest package registry in the world
  • Event-Driven - Perfect for building interactive applications
  • Large Community - Extensive resources and community support

Common Use Cases

  • Interactive Web Pages
  • Single Page Applications (React, Vue, Angular)
  • Web APIs and Services
  • Browser Extensions
  • Game Development
  • Data Visualization

Quick Start Example

Here’s a simple JavaScript program to get you started:

// Print Hello World
console.log("Hello, World!");

// Variables and data types
const name = "JavaScript";
let version = "ES2024";
var isAwesome = true;

console.log(`${name} ${version} is awesome: ${isAwesome}`);

// Arrays and loops
const numbers = [1, 2, 3, 4, 5];
numbers.forEach(num => {
  console.log(`Number: ${num}`);
});

// Functions
function greet(name) {
  return `Hello, ${name}!`;
}

console.log(greet("Developer"));

JavaScript Features

  • Dynamic Typing - Variables can hold any type of data
  • First-class Functions - Functions are objects and can be passed around
  • Prototypal Inheritance - Objects inherit from other objects
  • Closures - Functions can access outer scope variables
  • Async/Await - Modern asynchronous programming
  • Modules - ES6 module system for code organization

Modern JavaScript (ES6+)

  • Arrow Functions
  • Template Literals
  • Destructuring
  • Spread/Rest Operators
  • Promises and Async/Await
  • Classes

Learning Resources