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<p>From <b>http://www.w3schools.com</b> (Copyright Refsnes Data)</p>
<h1>Introduction to JavaScript</h1>
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<p class="intro">JavaScript is used in millions of Web pages to improve the
design, validate forms, detect browsers, create cookies, and much more.</p>
<p class="intro">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.</p>
<hr />
<h2>What You Should Already Know</h2>
<p>Before you continue you should have a basic understanding of the following:</p>
<ul>
<li>HTML / XHTML</li>
</ul>
<p>If you want to study these subjects first, find the tutorials on our
<a href="../default.asp">Home
page</a>.</p>
<hr />
<h2>What is JavaScript?</h2>
<ul>
<li>JavaScript was designed to add interactivity to HTML pages</li>
<li>JavaScript is a scripting language</li>
<li>A scripting language is a lightweight programming language</li>
<li>A JavaScript consists of lines of executable computer code</li>
<li>A JavaScript is usually embedded directly into HTML pages</li>
<li>JavaScript is an interpreted language (means that scripts execute without
preliminary compilation)</li>
<li>Everyone can use JavaScript without purchasing a
license</li>
</ul>
<hr />
<h2>Are Java and JavaScript the Same?</h2>
<p>NO!</p>
<p>Java and JavaScript are two completely different languages in both concept
and design!</p>
<p>Java (developed by Sun Microsystems) is a powerful and much more complex
programming language - in the same category as C and C++.</p>
<hr />
<h2>What can a JavaScript Do?</h2>
<ul>
<li><b>JavaScript gives HTML designers a programming tool - </b>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</li>
<li><b>JavaScript can put dynamic text into an HTML page - </b>A JavaScript statement like this: document.write("<h1>" + name +
"</h1>") can write a variable text into an HTML page</li>
<li><b>JavaScript can react to events - </b>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</li>
<li><b>JavaScript can read and write HTML elements - </b>A JavaScript can read
and change the content of an HTML element</li>
<li><b>JavaScript can be used to validate data - </b>A JavaScript can be used
to validate form data before it is submitted to a server. This saves the
server from extra processing</li>
<li><b>JavaScript can be used to detect the visitor's browser</b> - A
JavaScript can be used to detect the visitor's browser, and - depending on
the browser - load another page specifically designed for that browser</li>
<li><b>JavaScript can be used to create cookies</b> - A JavaScript can be
used to store and retrieve information on the visitor's computer</li>
</ul>
<hr />
<h2>The Real Name is ECMAScript</h2>
<p>JavaScript's official name is "ECMAScript". The standard is
developed and maintained by the
<a target="_blank" href="../../www.ecma-international.org/publications/index.html">
ECMA organisation</a>. </p>
<p>ECMA-262 is the official JavaScript standard. The standard is based on JavaScript (Netscape) and JScript (Microsoft). </p>
<p>The language was invented by Brendan
Eich at Netscape (with Navigator 2.0), and has appeared in all Netscape and Microsoft
browsers since 1996.</p>
<p>The development of ECMA-262 started in 1996, and the
first edition of was adopted by the ECMA General Assembly in June 1997.</p>
<p>The standard was approved as an international ISO (ISO/IEC
16262) standard in 1998.</p>
<p>The development of the standard is still in progress.</p>
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