Do I Need CDATA Sections Within Script Tags?

Are CDATA Sections Necessary Inside Script Tags?

A CDATA (character data) section is used to enclose text that should be treated as literal data by XML parsers. This can be useful when you need to include characters that would otherwise be interpreted as markup, such as "<" or "&".

In the context of script tags, CDATA sections are primarily used in XHTML documents. When an XHTML document is interpreted as XML (e.g., by an XML processor), any JavaScript code within the document is normally parsed as parsed character data. This means that certain characters, such as "<" and "&", will be interpreted as markup entities and replaced with their corresponding symbols.

To prevent this behavior, a CDATA section can be used to enclose the JavaScript code. This ensures that the code is treated as literal data and not parsed as markup.

For example, consider the following code:

This code will be interpreted as literal data by an XML parser, and the characters "<" and "&" will be preserved.
In contrast, the following code:

Will be parsed as parsed character data, and the characters "<" and "&" will be replaced with their corresponding symbols.
When to Use CDATA Sections
CDATA sections should be used any time you need to include characters within a script tag that would otherwise be interpreted as markup. This is especially important in XHTML documents that are intended to be parsed as XML.
Note: CDATA sections are not necessary for JavaScript code that is stored in external source files. This is because external files are not parsed as part of the XML document, and therefore, the characters "<" and "&" will not be interpreted as markup entities.
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