title: Does PHP 5.x have some kind of HashSet or Set Class?
body: <p>I'm used to Java where I have <code>HashSets</code>, <code>ArrayLists</code> and other <code>Collections</code>. But I'm workting on a PHP project right now.</p>
  
  <p>I need to create a set, fill that set with objects (Strings in this case), but the Set can only contain each object once. In addition I want to remove a certain object in the end from this set if it exists. This would be pretty easy with the Java collection classes. But how can I implement that in PHP?</p>
  
  <p>Are there any methods of <code>array()</code> that I am missing? I'm using PHP 5.3.</p>