title: How to add a new value to the end of an numerical array?
body: <p>In PHP I can do like:</p>
  
  <pre><code>$arrayname[] = 'value';
  </code></pre>
  
  <p>Then the value will be put in the last numerical key eg. 4 if the 3 keys already exists.</p>
  
  <p>In JavaScript I can’t do the same with:</p>
  
  <pre><code>arrayname[] = 'value';
  </code></pre>
  
  <p>How do you do it in JavaScript?</p>