CDATA vs PCDATA

CDATA (Character Data) and PCDATA (Parsed Character Data) are two types of data sections used in XML documents to handle character content differently. They serve different purposes and have distinct rules for handling special characters.

1. CDATA (Character Data):

• CDATA sections are used to represent character data that should be ignored by the XML parser and treated as raw character content.
• CDATA sections are useful when the character data contains special characters like angle brackets (“<” and “>”) or ampersands (“&”) that would otherwise be interpreted as XML markup.
• CDATA sections start with the <![CDATA[ delimiter and end with the ]]> delimiter.
• The content within a CDATA section is not parsed by the XML processor, and it can contain any characters, including XML reserved characters, without any need for escaping. Example:

   <description><![CDATA[This is a <b>bold</b> &amp; italic text.]]></description>

2. PCDATA (Parsed Character Data):

• PCDATA sections are used to represent character data that should be parsed and interpreted by the XML processor.
• PCDATA sections are the default type of character data in XML elements, and they allow XML markup and entity references to be processed.
• PCDATA sections are subject to XML rules and need to escape special characters that have special meaning in XML, such as angle brackets (“<” and “>”) and ampersands (“&”). Example:

   <title>This is a &lt;b&gt;bold&lt;/b&gt; &amp; italic text.</title>

In summary, CDATA sections are used when you want to include character data that contains special characters and you don’t want the XML processor to interpret them as markup. The content within CDATA sections is treated as plain text and is not subject to XML parsing rules.

On the other hand, PCDATA sections are used for character data that needs to be parsed and processed as XML content, following the standard XML rules for special characters and entity references.

The choice between using CDATA and PCDATA depends on the content you want to represent and how you want the XML processor to handle that content. If you want to include unescaped special characters or avoid XML parsing altogether, you can use CDATA sections. Otherwise, PCDATA sections are used for regular character content that follows standard XML rules.