title: Remove a set of fields from a array
body: <p>Is there a native PHP function that can remove a set of keys from a array?</p>
  
  <p>for eg. if I have a array like
  <code>array('a' =&gt; 'aaa', 'b' =&gt; 'bbb', 'c' =&gt; 'ccc', 'd' =&gt; 'ddd');</code></p>
  
  <p>and I want to remove <code>'b', 'c'</code> and get <code>array('a' =&gt; 'aaa', 'd' =&gt; 'ddd');</code> ?</p>