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Changes in XHTML

Recently, with the advent of the XHTML standard (eXtensible HTML), the

tag has under-

gone a change. Instead of the

language

attribute, the tag is now expected to have a

type

attribute to

indicate the mime type of the inline code or external file being included; the mime type for JavaScript is

“text/javascript”

. For example:

<html>

<head>

<title>Title of Page</title>

var i = 0;

</script>

</head>

<body>

</body>

</html>

Even though many browsers don’t fully support XHTML, most developers are now using the

type

attribute in place of the

language

attribute in anticipation of better XHTML support. Omitting the

language

attribute doesn’t cause any problems because, as noted earlier, all browsers default to

JavaScript for the

tag.

The second change in XHTML is the use of CDATA sections. CDATA sections are used in XML (and,

therefore, in XHTML) to indicate text that should not be parsed as tags, allowing the use of special char-

acters such as the less-than (

), greater-than (

), ampersand (

), and double quotes (

“

) without using

their character entities. Consider the following code:

function compare(a, b) {

if (a < b) {

alert(“A is less than B”);

} else if (a > b) {

alert(“A is greater than B”);

} else {

alert(“A is equal to B”);

}

</script>

This is a fairly simple function, which just compares two numbers,

and

, and then displays a message

indicating their relationship. In XHTML, however, this code is invalid because it uses three special char-

acters, less-than, greater-than, and double-quote. To fix this, you must replace these characters with their

XML entities,

, and

, respectively:

function compare(a, b) {

if (a < b) {

alert("A is less than B");

} else if (a > b) {

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JavaScript in the Browser

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