Question

In html files, you probably can write:

<script type="aaa/bbb" src="xyz.js"></script> language=”javascript”

In JavaScript files (.js) it is just the raw JavaScript codes without specifying the type, is it assuming all types are “text/javascript”? What if you have typed like “aaa/bbb”?

Dojo is an example may require this.

Answer 1

Yes, in a JavaScript file you just write the code without any tags around it. It’s the tag that includes the file in the page that specifies the type. So you might have:

foo.js:

function doSomethingReallyCool() {
   // ...
}

…which you include like this:

<script src="foo.js"></script>

You can optionally specify the type on the script element:

<script type="text/javascript" src="foo.js"></script>

…but in practice this is unnecessary for JavaScript, you’d only need it if you were referencing a file that wasn’t JavaScript (like VBScript on IE).

Note that the language attribute in your example was never part of any specification. Since HTML 4 (12 years ago), the correct way to indicate the language is via the type attribute.