title: sum values of an array when keys are not values of another array
body: <p>i have 2 arrays:</p>
  
  <pre><code>$a=Array 
  ( 
  [25] =&gt; 21.00 
  [33] =&gt; 63.00
  [12] =&gt; 45.00
  [14] =&gt; 12.00
  [17] =&gt; 22.00
  )
  $b=Array
  (
  [0] =&gt; 24 
  [1] =&gt; 25 
  [3] =&gt; 14
  ) 
  </code></pre>
  
  <p>I want to sum only the values of array $a that their keys do not much the values of array $b.
  For instance in this example the output would be 130.
  Any idea would be appreciated.Thanks in advance!  </p>