JavaScript is the most popular programming language in the world.
This page contains some examples of what JavaScript can do.
JavaScript Can Change HTML Content
One of many HTML methods is getElementById().
This example uses the method to "find" an HTML element (with id="demo"), and changes the element content (innerHTML) to "Hello JavaScript":
JavaScript Can Change HTML Attributes
This example changes an HTML image, by changing the src attribute of an <img> tag:
The Light Bulb
JavaScript Can Change HTML Styles (CSS)
Changing the style of an HTML element, is a variant of changing an HTML attribute:
JavaScript Can Validate Data
JavaScript is often used to validate input:
Please input a number between 1 and 10
Try it Yourself »Did You Know?
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.