What is JavaScript?

JavaScript is the programming language of HTML and the Web. It is one of the 3 languages all web developers must learn:

HTML to define the content of web pages
CSS to specify the layout of web pages
JavaScript to program the behavior of web pages

This tutorial is about JavaScript, and how JavaScript works with HTML and CSS. Programming makes computers do what you want them to do. A simple example of Javascript is shown here:

HTML file:	Displayed by browser:
<!DOCTYPE html> <html> <body> <h1>My First JavaScript</h1> <button type="button" onclick="document.getElementById('demo').innerHTML = Date()"> Click me to display Date and Time.</button> <p id="demo"></p> </body> </html>	My First JavaScript

HTML file:

Displayed by browser:

<!DOCTYPE html>
<html>
<body>

<h1>My First JavaScript</h1>

<button type="button"
onclick="document.getElementById('demo').innerHTML = Date()">
Click me to display Date and Time.</button>

<p id="demo"></p>

</body>
</html>

My First JavaScript

JavaScript and Java are completely different languages, both in concept and design. JavaScript was invented by Brendan Eich in 1995, and became an ECMA standard in 1997. ECMA-262 is the official name. ECMAScript 6 (released in June 2015) is the latest official version of JavaScript.