JavaScript is an implementation of the ECMAScript language standard and is typically used to enable programmatic access to computational objects within a host environment. It can be characterized as a prototype-based object-oriented scripting language that is dynamic, weakly typed and has first-class functions. It is also considered a functional programming language like Scheme and OCaml because it has closures and supports higher-order functions.
JavaScript is primarily used in the form of client-side JavaScript, implemented as part of a web browser in order to provide enhanced user interfaces and dynamic websites. However, its use in applications outside web pages is also significant.
JavaScript uses syntax influenced by that of C syntax, also JavaScript copies many Java programming language names and naming conventions; but the two languages are otherwise unrelated and have very different semantics. The key design principles within JavaScript are taken from the Self and Scheme programming languages.
Example - use in web pages:
A minimal example of a standards-conforming web page containing JavaScript (using HTML 4.01 syntax) would be the following:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head><title>simple page</title></head>
<body>
<script type="text/javascript">
document.write('Hello World!');
</script>
<noscript>
Your browser either does not support JavaScript, or you have JavaScript turned off.
</noscript>
</body>
</html>
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