W3Schools

home HOME

JS Basic
JS HOME
JS Introduction
JS How To
JS Where To
JS Statements
JS Comments
JS Variables
JS Operators
JS Comparisons
JS If...Else
JS Switch
JS Popup Boxes
JS Functions
JS For Loop
JS While Loop
JS Break Loops
JS For...In
JS Events
JS Try...Catch
JS Throw
JS onerror
JS Special Text
JS Guidelines

JS Objects
JS Objects Intro
JS String
JS Date
JS Array
JS Boolean
JS Math
JS RegExp
JS HTML DOM

JS Advanced
JS Browser
JS Cookies
JS Validation
JS Animation
JS Image Maps
JS Timing
JS Create Object
JS Summary

Examples/Quiz
JS Examples
JS Object Examples
JS DOM Examples
JS Quiz

JS References
JS Objects
JS HTML DOM

Selected Reading
Web Statistics
Web Glossary
Web Hosting
Web Quality

W3Schools Forum

Helping W3Schools

Introduction to JavaScript

previous next

JavaScript is used in millions of Web pages to improve the design, validate forms, detect browsers, create cookies, and much more.

JavaScript is the most popular scripting language on the internet, and works in all major browsers, such as Internet Explorer, Mozilla, Firefox, Netscape, and Opera.


What You Should Already Know

Before you continue you should have a basic understanding of the following:

  • HTML / XHTML

If you want to study these subjects first, find the tutorials on our Home page.


What is JavaScript?

  • JavaScript was designed to add interactivity to HTML pages
  • JavaScript is a scripting language
  • A scripting language is a lightweight programming language
  • A JavaScript consists of lines of executable computer code
  • A JavaScript is usually embedded directly into HTML pages
  • JavaScript is an interpreted language (means that scripts execute without preliminary compilation)
  • Everyone can use JavaScript without purchasing a license

Are Java and JavaScript the Same?

NO!

Java and JavaScript are two completely different languages in both concept and design!

Java (developed by Sun Microsystems) is a powerful and much more complex programming language - in the same category as C and C++.


What can a JavaScript Do?

  • JavaScript gives HTML designers a programming tool - HTML authors are normally not programmers, but JavaScript is a scripting language with a very simple syntax! Almost anyone can put small "snippets" of code into their HTML pages
  • JavaScript can put dynamic text into an HTML page - A JavaScript statement like this: document.write("<h1>" + name + "</h1>") can write a variable text into an HTML page
  • JavaScript can react to events - A JavaScript can be set to execute when something happens, like when a page has finished loading or when a user clicks on an HTML element
  • JavaScript can read and write HTML elements - A JavaScript can read and change the content of an HTML element
  • JavaScript can be used to validate data - A JavaScript can be used to validate form data before it is submitted to a server. This saves the server from extra processing
  • JavaScript can be used to detect the visitor's browser - A JavaScript can be used to detect the visitor's browser, and - depending on the browser - load another page specifically designed for that browser
  • JavaScript can be used to create cookies - A JavaScript can be used to store and retrieve information on the visitor's computer

The Real Name is ECMAScript

JavaScript's official name is "ECMAScript". The standard is developed and maintained by the ECMA organisation

ECMA-262 is the official JavaScript standard. The standard is based on JavaScript (Netscape) and JScript (Microsoft).

The language was invented by Brendan Eich at Netscape (with Navigator 2.0), and has appeared in all Netscape and Microsoft browsers since 1996.

The development of ECMA-262 started in 1996, and the first edition of was adopted by the ECMA General Assembly in June 1997.

The standard was approved as an international ISO (ISO/IEC 16262) standard in 1998.

The development of the standard is still in progress.


previous next


Learn XML with <oXygen/> XML Editor - Free Trial!

oXygen - Probably The World's Best XML Editor   

oXygen helps you learn to define, edit, validate and transform XML documents. Supported technologies include XML Schema, DTD, Relax NG, XSLT, XPath, XQuery, CSS.

Understand in no time how XSLT and XQuery work by using the intuitive oXygen debugger!

Do you have any XML related questions? Get free answers from the oXygen XML forum and from the video demonstrations.

Download a FREE 30-day trial today!




Jump to: Top of Page or HOME or Printer Friendly Printer friendly page

W3Schools provides material for training only. We do not warrant the correctness of its contents. The risk from using it lies entirely with the user. While using this site, you agree to have read and accepted our terms of use and privacy policy.

Copyright 1999-2008 by Refsnes Data. All Rights Reserved.

Validate Validate W3C-WAI level A conformance icon W3Schools was converted to XHTML in December 1999