title: Filter an array with array_filter
body: <p>I have an array of words and an array of stopwords. I want to remove those words from the array of words that are in the stopwords array, but the code returns all words:</p>
  
  <pre><code>function stopwords($x){
        return !preg_match("/^(.|a|car|red|the|this|at|in|or|of|is|for|to)$/",$x);
      };
  
  $filteredArray = array_filter($wordArray, "stopwords");
  </code></pre>
  
  <p>Why?</p>