CDATA – (Unparsed) Character Data
The term CDATA is used about text data that should not be parsed by the XML parser.
Characters like “<” and “&” are illegal in XML elements.
“<” will generate an error because the parser interprets it as the start of a new element.
“&” will generate an error because the parser interprets it as the start of an character entity.
Some text, like JavaScript code, contains a lot of “<” or “&” characters. To avoid errors script code can be defined as CDATA.
Everything inside a CDATA section is ignored by the parser.
A CDATA section starts with “<![CDATA[” and ends with “]]>“:
<![CDATA[
function matchwo(a,b)
{
if (a < b && a < 0) then
{
return 1;
}
else
{
return 0;
}
}
]]>
</script>
In the example above, everything inside the CDATA section is ignored by the parser.
Notes on CDATA sections:
A CDATA section cannot contain the string “]]>”. Nested CDATA sections are not allowed.
The “]]>” that marks the end of the CDATA section cannot contain spaces or line breaks.