Returns true if the value of the first item is less than or equal to the value of the second item.
Syntax
valueA <= valueBExample
var foo = 3;
if (foo <= 5)
return true; //Returns true because foo == 3.本文档基于 CC协议（Creative Commons Share-Alike License）发布，是developer.mozilla.com, www.mozref.com和www.aptana.com共同劳动的成果。