Using HTML Entities to Protect HTML Tags

This section provides a tutorial example on how to use HTML entities < and > to protext HTML tags

To completely resolve the problem we saw in the previous section, we need to use HTML entities to replace '<' and '>', if you want some HTML tags to be displayed as page content.

Here is the revised HTML document using &lt; and &gt; entities:

<html>
<!-- Escape_Script_Tag_HTML_Entity.html
   Copyright (c) 2013 by Dr. Herong Yang, herongyang.com
-->
<head><title>Escaping Script Tags</title></head>
<body><pre>
<script type="text/javascript">
   document.writeln("Q: How to use the &lt;script&gt; tag?");
   document.writeln("A: &lt;script&gt;...Code...&lt;\/script&gt;");
   document.writeln("Rate this answer: 1 | 2 | 3 | 4 | 5");
</script>
</pre></body>
</html>

If you run this example script in a browser, you will get:

Q: How to use the <script> tag?
A: <script>...Code...</script>
Rate this answer: 1 | 2 | 3 | 4 | 5

Finally, we get what we want!

Table of Contents

 About This Book

 Introduction to JavaScript

 ECMAScript Language Specification and JavaScript Dialects

 Data Types, Variables and Expressions

 Flow Control Statements

 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

 Including 'script' Tags in String Literials

 Escaping 'script' Tags in String Literials

Using HTML Entities to Protect HTML Tags

 Including JavaScript Codes as External Files

 DOM API - The "document" Object

 DOM API - The "window" Object

 DOM API - The "window.open" Method

 Event Listeners and Objects

 'javascript:' Pseudo-URL Addresses

 Server-Side and Client-Side Web Scripting

 Introduction to Objects

 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

 References

 PDF Printing Version