title: Passing an optional parameter in PHP Function
body: <p>How can I pass an optional parameter to a PHP function. For example</p>
  
  <pre><code>function test($required, $optional){..}
  </code></pre>
  
  <p>So that i should be able to call the function by passing either one parameter or both. For example:</p>
  
  <pre><code>test($required, $optional)
  test($required);
  </code></pre>
  
  <p>Thanks.</p>