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JavaScript

JavaScript is a programming language used to add behavior to websites, build servers, create tools, and develop full applications.

What Is JavaScript​

JavaScript runs in browsers and in runtimes such as Node.js, Bun, and Deno.

It is commonly used for interactive interfaces, API calls, backend services, command-line tools, and automation.

How To Use JavaScript​

In the browser, add JavaScript with a script tag. In Node.js, create a .js file and run it with node.

Basic Example​

const message = "Hello, JavaScript";

function greet(name) {
  return `${message}. Welcome, ${name}.`;
}

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

Common Concepts​

  • Variables store values with const and let.
  • Functions group reusable behavior.
  • Objects and arrays model data.
  • Promises and async/await handle asynchronous work.

What To Learn Next​

Learn DOM manipulation, modules, fetch requests, error handling, testing, and modern JavaScript tooling.