title: Help me to understand piece of PHP code
body: <p>I'm trying to give default values to variables if there is no $_GET for them. There is 1 method with <code>if(isset(...))</code> but it's writing bunch of code for every variable. While researching for another solution found this piece of code. Can anyone help me to understand second line of code?</p>
  
  <pre><code>$defaults = array('page' =&gt; 'main', 'lang' =&gt; 'en');
  foreach ($defaults as $k =&gt; $v) $$k = isset($_GET[$k])? $_GET[$k] : $v;
  </code></pre>