title: array_unique not removing duplicates
body: <p>I got an issue with <code>array_unique</code> where duplicate values are not being removed.</p>
  
  <pre><code>&lt;?php
      $mfgName = 'blah';
      $prodModel = '178.211';
      $name ='178.211 remove this number';
  
      $input = array($mfgName, $prodModel, $name);
      $st =array_unique($input);
      $str= implode(' ', $st);
      echo $str;
  ?&gt;
  </code></pre>
  
  <p>Output should be:</p>
  
  <pre><code>blah 178.211 remove this number
  </code></pre>
  
  <p>but I get:</p>
  
  <pre><code>blah 178.211 178.211 remove this number
  </code></pre>