title: Class name before variable in PHP function argument
body: <p>In lots of PHP scripts I see things such as this:</p>
  
  <pre><code>public function __construct(Container $ci) {
  
  }
  </code></pre>
  
  <p>I understand what a constructor does and how to pass a variable. However I'm not sure what <code>Container</code> means in this example? Is this the equivalent of <code>$ci = new Container;</code> ?</p>