<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Arr</title>
<script>
//栈
/*-----------------------------------------------push()---------------------------------------*/
//Array中的push():逐个添加在数组的末尾，返回数组的长度
/*
* arr = [1,2,3];
* arr.push(4)
* arr = [1,2,3,4];
* arr.length = 4;
* */
Array.prototype.yjPush = function () {
var arr = this;
for(var i = 0;i<arguments.length;i++){
arr[arr.length] = arguments[i];
}
return arr.length;
};
var arr = [1,2,3];
var val = arr.yjPush("hello",5,"ddd");
console.log(arr);
console.log(val);
/*-------------------------------------------------pop()-------------------------------------*/
//Array中的pop():从数组的末尾移除最后一项，减少数组的length值，返回移除的项。
/*
* arr = [1,2,3];
* arr.pop();
* arr = [1,2];
* */
Array.prototype.yjPop = function () {
var remove = this[this.length-1];
this.length = this.length-1;
return remove;
};
var arr = [1,2,3];
var val = arr.yjPop();
console.log(arr);
console.log(val);
//队列
/*--------------------------------------------------shift()-----------------------------------*/
//Array中的shift():移除数组中的第一项，并且返回该项，同时将数组的长度减1
/*
* arr = [1,2,3];
* arr.shift();
* arr = [2,3];
* */
Array.prototype.yjShift = function () {
var remove = this[0];
for(var i = 0;i<this.length;i++){
this[i] = this[i+1];
}
this.length = this.length-1;
return remove;
};
var arr = [1,2,3];
var val = arr.yjShift();
console.log(arr);
console.log(val);
/*-----------------------------------------------unshift()----------------------------------------*/
//Array中的unshift():在数组的前端添加任意个项，并返回新数组的长度
/*
* arr = [1,2,3];
* arr.unshift(4,5);
* arr = [4,5,1,2,3];
* */
Array.prototype.yjUnshift = function () {
this.length = this.length+arguments.length;//5
for(j = this.length-1;j>arguments.length-1;j--){
this[j] = this[j-2];
}
for(var i = 0;i<arguments.length;i++){
this[i] = arguments[i];
}
return this.length;
};
var arr = [1,2,3];
var val = arr.yjUnshift("hello",5);
console.log(arr);
console.log(val);
</script>
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