PHP $_POST and id only, no name

Question

Can someone please explain this to me?

I have the following code:

<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
 <input type="text" id="testField" />
 <input type="submit">
</form>
<br /><br />
<pre>
 <?php print_r($_POST); ?>
</pre>

This works fine on my main dev box, and on the server. However, I'm having to work remotely on my laptop at the moment. I've installed the exact same WAMPServer 2.1a build as on my dev setup, and the $_POST array is empty.

If I declare the field like:

<input type="text" name="testField" />

I get the expected output.

Answer 1

Standard behavior. Always use name within form.

Answer 2

From the HTML 4.01 specification, §17.2, "Controls":

A control's "control name" is given by its name attribute.

...

When a form is submitted for processing, some controls have their name paired with their current value and these pairs are submitted with the form.

"id" does not matter.