集合转数组函数

 1 function toArray(coll) {

 2     for (var i = 0, a = [], len = coll.length; i < len; i++) {

 3         a[i] = coll[i];

 4     }

 5     return a;

 6 }

 7 

 8 //用法

 9 var coll = document.getElementsByTagName('div');

10 var arr = toArray(coll);