Merge two arrays in PHP
<p>I have two arrays:</p>

<pre><code>$a = array([0]=&gt;1 [1]=&gt;2 [2]=&gt;3);
$b = array([0]=&gt;a [1]=&gt;b [2]=&gt;c);
</code></pre>

<p>I want to merge them like</p>

<pre><code>$ab=array( [a]=&gt;array([0]=&gt;1 [1]=&gt;2 [2]=&gt;3) 
           [b]=&gt;array([0]=&gt;a [1]=&gt;b [2]=&gt;c)  );
</code></pre>

<p>How to do this ?</p>

<p>I tried <code>array_merge()</code> but it does not work as I want it to.</p>
