title: is concat faster or slower than push
body: <p>For this code I want to know in javascript what is the best approach?</p>
  
  <pre><code>var output = foo +";"+bar;
  </code></pre>
  
  <p>or</p>
  
  <pre><code>var output = new Array(foo,bar).join(";");
  </code></pre>