JavaScript Tutorial · JavaScript Basics · Lesson 2 of 44

JavaScript Get Started

Run JavaScript in the browser, in a web page and with Node.js.

Three ways to run JavaScript

1. In this tutorial. Every example has a Run button and an Edit & try it yourself mode — nothing to install.

2. In a web page. Put code in a <script> tag, or in a separate .js file loaded with <script src="app.js"></script>:

JavaScript inside a web pageTry it yourself

<!DOCTYPE html>
<html>
<body>
  <h1 id="title">Hello</h1>
  <script>
    document.getElementById("title").textContent = "Hello from JavaScript!";
  </script>
</body>
</html>

3. With Node.js. Install Node.js from nodejs.org (choose the LTS version), save code in app.js, and run it from a terminal:

node --version
node app.js

The browser console

Open any web page, press F12 (or Cmd+Option+I on macOS) and choose Console. You can type JavaScript there and see the result immediately — perfect for quick experiments.

Example 2Try it yourself

console.log(2 + 3);
console.log("Learning " + "JavaScript");

Output

5
Learning JavaScript

Test yourself

Which HTML tag holds JavaScript code?

<js>
<javascript>
<script>
<code>

Show answer

Answer: <script>