title: PHP array index how to unset it
body: <p>I have example those values:</p>
  
  <pre><code>$waiting['s9d8393838333'][] = array("client_id" =&gt; "2039833");
  $waiting['s9d8393838333'][] = array("client_id" =&gt; "1039833");
  </code></pre>
  
  <p>How can i delete a client_id from the array? ex if i will delete client_id => 2039833 ?</p>
  
  <pre><code>foreach ( $waiting as $e =&gt; $array):
      if ( $array['client_id'] == $clientID):
           //Here i should delete that index ???
      endif;
  endforeach;
  </code></pre>