JavaScript Tutorials - Herong's Tutorial Examples - 2.33, by Herong Yang
Client-Side Scripting Processed Multiple Times
This section provides a tutorial example of a JavaScript code inserts another JavaScript code back into the HTML document. The Web browser executes script code multiple times.
As we learned earlier, when the Web browser receives the HTML document from the Web server, it will remove all embedded script codes and execute them.
What happens if a new script code is inserted back into the HTML document during the first round of script execution? The Web browser will remove the inserted script code and execute it again.
Here is an interesting tutorial example of a JavaScript code that inserts another JavaScript code into the HTML document:
<html>
<!-- Hello_Nested_Scripts.html
Copyright (c) 2008 HerongYang.com. All Rights Reserved.
-->
<head><title>Hello from Nested Scripts</title></head>
<body><pre>
<script type="text/javascript">
document.writeln("Hello World!");
document.writeln("<script type=\"text/javascript\">");
document.writeln("document.writeln(\" Hello World!\");");
document.writeln("<\/script>");
</script>
</pre></body>
</html>
Take a guess on what you will see on the browser window if you run this HTML document.
Hello World! Hello World!
What happens is that when the browser finishes the execution of the embedded JavaScript code, it will get the following the HTML document:
Hello World!
<script type="text/javascript">
document.writeln(" Hello World!");
</script>
There is another JavaScript code in the output. The browser will execute it again resulting the final HTML document you saw earlier.
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
►Server-Side and Client-Side Web Scripting
Web Scripting Architecture Overview
Server-Side Scripting Overview
Client-Side Scripts for Document Updating
Client-Side Scripts for Event Handling
►Client-Side Scripting Processed Multiple Times
New Script Resulted from Two Original Scripts
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