title: C#'s null coalescing operator (??) in PHP
body: <p>Is there a ternary operator or the like in PHP that acts like <code>??</code> of C#?</p>
  
  <p><code>??</code> in C# is clean and shorter, but in PHP you have to do something like:</p>
  
  <pre><code>// This is absolutely okay except that $_REQUEST['test'] is kind of redundant.
  echo isset($_REQUEST['test'])? $_REQUEST['test'] : 'hi';
  
  // This is perfect! Shorter and cleaner, but only in this situation.
  echo null? : 'replacement if empty';
  
  // This line gives error when $_REQUEST['test'] is NOT set.
  echo $_REQUEST['test']?: 'hi';
  </code></pre>