how change part of url by preg_replace?
<p>I am trying to change all the links of a html with php preg_replace. All the uris have the following form</p>

<pre><code>test.com/item/16
</code></pre>

<p>I want to change it to:</p>

<pre><code>test.com/z/item/16
</code></pre>

<p>I tried the following, but it returns no changes:</p>

<pre><code>$links = 'http://test.com/item/16';
preg_replace("/item","z/item",$links);

echo $links; 
// output &gt;&gt;&gt; http://test.com/z/item/16
</code></pre>