adding a key-value pair to inner array
<p>I already have data in array as</p>

<pre><code> $a = array (
     [2011-07-09] =&gt; array(['new'] =&gt; 12),
     [2011-07-10] =&gt; array(['new'] =&gt; 15)
 );
</code></pre>

<p>Now I want to add another key-value pair to inner array so that output will be like</p>

<pre><code> $a = array (
     [2011-07-09] =&gt; array(['new'] =&gt; 12, ['recurring'] =&gt; 52),
     [2011-07-10] =&gt; array(['new'] =&gt; 15, ['recurring'] =&gt; 80)
 );
</code></pre>

<p>How can I do this?</p>
