Yes, it does.
Sometimes it's convenient to use "HTML arrays", meaning to name fields like:
<input name="something" />
Then on the server side you loop through the array
This allows for a flexibility where your app doesn't know the number of inputs in advance, but works fine regardless of the actual number.
The problem is if you want to do some sort of client-side validation after you've generated fields on the fly. If you have:
<input name="something" /> <input name="something" /> <input name="something" />
Then you can access the fields using
So in the case above
will give you 3.
Then you add another fields, for example like:
var new_input = document.createElement('input'); new_input.type = 'text'; new_input.name = 'something'; document.body.appendChild(new_input);
Now if you try to count the fields with
you'll get 4 in Firefox as you would expect, but still 3 in IE.
Bugs happen, c'est la vie
Tested IE7 only, don't know if the bug exists in earlier versions.