如题,包括实现pop push 的返回值
push 的实现:
function pushArr(arr, value) {
arr[arr.length] = value;
return arr;
}
var arr = [];
pushArr(arr, 1);
pop 的实现:
function popArr(arr) {
if(arr.length === 0) return undefined;
var temp = arr[arr.length-1];
arr.length--;
return temp;
}
var arr = [1,2,3,4,5,6];
popArr(arr);
Array.prototype._push = function(item) {
this[this.length] = item;
return this.length;
}
Array.prototype._pop = function() {
if (this.length === 0) return void 0;
var temp = this[this.length - 1];
this.length--;
return temp;
}