title: Find max value of array
body: <p>I'm trying to find the max value of an array</p>
  
  <pre><code>function highestNumb(arr) {
    Math.max.apply(Math, arr);
  }
  
  highestNumb([12,4,6,0]);
  </code></pre>
  
  <p>Why do I keep getting <em>undefined</em>?</p>