类数组对象转化为数组后才可被遍历,可使用以下方法转换：

1. Array.from()
2. Array.prototype.slice.call()
3. [...elems]
4. Array.prototype.forEach.call(elem,callback)
5. Array.prototype.forEach.apply(elem,[callback])
6. Array.prototype.forEach.bind(elemlist)

let list = Array.from(somelist);

let list = Array.prototype.slice.call(somelist);

let list = [...somelist];

Array.prototype.forEach.call(somelist,function(){
	...
})

Array.prototype.map.call(somelist,function(){
	...
})

Array.prototype.map.call(somelist,[(current,index) => {
	...
}]);

Array.prototype.forEach.bind(somelist)((current,index) => {
	...
});