How does ["$field"] in PHP work?
<p>Hi I have problem understanding the code below:</p>

<pre><code>foreach ($_POST as $field=&gt;$value) { 
   $this-&gt;ipn_data["$field"] = $value;
   $post_string .= $field.'='.urlencode(stripslashes($value)).'&amp;'; 
}
</code></pre>

<p>What does <code>$this-&gt;ipn_data["$field"] = $value</code> do? I need some examples to understand this.</p>
