Is there a way to implement a StringBuilder in JavaScript
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/112158/javascript-string-concatenation">JavaScript string concatenation</a><br>
  <a href="http://stackoverflow.com/questions/2087522/does-javascript-have-a-built-in-stringbuilder-class">does javascript have a built in stringbuilder class?</a>  </p>
</blockquote>



<p>As it's known when we do <code>str = str + "123"</code> a new string is created. If we have a large number of concatenations it can be rather expensive. Is there a simple way to implement a StringBuilder in JavaScript?</p>
