The comma operator in JavaScript.

Take a look at this:<p><a href="http://jsfiddle.net/RfZed/2/" rel="nofollow">http:&#x2F;&#x2F;jsfiddle.net&#x2F;RfZed&#x2F;2&#x2F;</a>

var x = 5, y = 6 &#x2F;&#x2F; typical JS<p>(2,4) &#x2F;&#x2F; returns 4<p>thus,<p>test(2,4) adds 0, 2 and 4<p>test((2, 4)) adds 0 and 4