title: Add a prefix to each item of a PHP array
body: <p>I have a PHP array of numbers, which I would like to prefix with a minus (-). I think through the use of explode and implode it would be possible but my knowledge of php is not possible to actually do it. Any help would be appreciated.</p>
  
  <p>Essentially I would like to go from this:</p>
  
  <pre><code>$array = [1, 2, 3, 4, 5];
  </code></pre>
  
  <p>to this:</p>
  
  <pre><code>$array = [-1, -2, -3, -4, -5];
  </code></pre>
  
  <p>Any ideas?</p>