Array.prototype.slice.call
Array.prototype.slice.call(arguments)能将具有length属性的对象转成数组
1 var arr={length:2,0:'name',1:'age'}; 2 Array.prototype.slice.call(arr);// ["name", "age"] 3 4 var arr={length:2}; 5 Array.prototype.slice.call(arr);// [undefined, undefined]
