From well formatted string to an array
<p>In JavaScript, what is the best way to convert a well formatted string (<code>"4,5,7,2"</code>) to an array (<code>[4,5,7,2]</code>):</p>

<p><code>var _intStr="3,5,7,8"</code> &rarr; <code>var _intArr=[3,5,7,8]</code></p>
