title: php - get last index of a multidimensional array
body: <p>As I read though how to get the last value of multidimensional array, end(array) has come up multiples times. 
  My problem is similar, I have an array like this:</p>
  
  <pre><code>array = (
  [12] =&gt; Array (xxx =&gt; xxx),
  [34] =&gt; Array (xxx =&gt; xxx),
  [56] =&gt; Array (yyy =&gt; yyy)
  );
  </code></pre>
  
  <p>I want to get the index number. If I use end(array) I will get the whole array indexed from [56]. How do I get [56] itself instead of the array?</p>
  
  <p>P.S. I know I can use loop to get the last index number, I just don't want to loop though the whole array to just get the last index number...</p>