title: Php array subtract values
body: <p>I have following array:</p>
  
  <pre><code>array(50,6,8,9)
  </code></pre>
  
  <p>I wanna subtract all values on array</p>
  
  <p>Result must be: (50-6-8-9=equals):</p>
  
  <pre><code>27
  </code></pre>
  
  <p>Something like <code>array_sum</code> but unlike !</p>