JavaScript Tutorials - Herong's Tutorial Examples - 2.33, by Herong Yang
Including JavaScript Codes with HTML "script" Tags
This section provides a quick description of how to include JavaScript codes into HTML documents with 'script' tags. A tutorial example is provided on calling a function defined in the 'head' tag.
JavaScript code is designed to be executed mainly by Web browsers on client systems. So JavaScript code needs to be embedded in HTML documents to be delivered to browsers.
HTML document language standard supports the "script" tag that allows you to include JavaScript code in HTML documents. The syntax of the "script" tag looks like this:
<script type="text/javascript" ...> ... JavaScript statements ... </script>
In a single HTML document, multiple "script" tags with JavaScript codes can be placed in different locations. The exact locations and relations of "script" tags are described in following simple rules:
Based these rules, we could define a user function in the "head" tag of the document, and call it later in a "pre" tag in the same document. Here is a simple tutorial example that shows this interesting behavior:
<html> <!-- Hello_World_Head.html Copyright (c) 2008 HerongYang.com. All Rights Reserved. --> <head> <title>printHello() Function in the "head" Tag</title> <script type="text/javascript"> function printHello() { document.write('Hello World!'); } </script> </head> <body> <pre> <script type="text/javascript"> printHello(); </script> </pre> </body> </html>
Of course, the output of this sample JavaScript page will be a simple text on the page: "Hello World!".
Table of Contents
ECMAScript Language Specification and JavaScript Dialects
Data Types, Variables and Expressions
Creating, Accessing, and Manipulating Arrays
Defining and Calling Functions
►Web Browser Supporting JavaScript
JavaScript Support in Web Browsers
►Including JavaScript Codes with HTML "script" Tags
type="text/javascript" or language="JavaScript"
JavaScript Version Supported by Browsers
Including 'script' Tags in String Literals
Escaping 'script' Tags in String Literals
Using HTML Entities to Protect HTML Tags
Including JavaScript Codes as External Files
DOM API - The "document" Object
DOM API - The "window.open" Method
'javascript:' Pseudo-URL Addresses
JavaScript Console in Google Chrome
JavaScript Console in Mozilla Firefox
JavaScript Console in Apple Safari
JavaScript Console in IE (Internet Explorer)
Server-Side and Client-Side Web Scripting
Defining Your Own Object Types
Inheritance of Properties and Methods through the Prototype Object Chain
'jrunscript' - JavaScript Shell Command from JDK
Using Functions as "Function" Objects
Introduction to Built-in Object Types
W3C's Document Object Model (DOM) Specifications