JS數組移除元素的方法

1. 修改Arr的length
   let arr = [1,2,3,4,5,6,7,8,9];
   arr.length = 3;
   console.log('length',arr.length);
   console.log('arr',arr);

2.delete (修改Arr的內容,但length不變)
let arr = [1,2,3,4,5,6,7,8,9];
delete arr[2];
console.log('length',arr.length);
console.log('arr',arr);

3.pop(棧方法,刪除Arr的最后一個元素)
let arr = [1,2,3,4,5,6,7,8,9];
arr.pop();
console.log('length',arr.length);
console.log('arr',arr);

4.shift(刪除Arr的第一位元素)
let arr = [1,2,3,4,5,6,7,8,9];
arr.shift();
console.log('length',arr.length);
console.log('arr',arr);

5.splice(可以對Arr進行增刪改操作, 這里只寫刪除方法)
let arr = [1,2,3,4,5,6,7,8,9];
arr.splice(0,2);
// 第一位參數 0: 代表的是起始下標注
// 第二位參數 2: 代表的是刪除的位數
console.log('length',arr.length);
console.log('arr',arr);

6.forEach || filter (通過迭代循環,刪除元素)
let arr = [1,2,3,4,5,6,7,8,9];
arr.forEach((item,index,arr) => {
if(item === 3){
arr.splice(index,1)
}
});
console.log('length',arr.length);
console.log('arr',arr);
let arr = [1,2,3,4,5,6,7,8,9];
arr = arr.filter((item)=>{
return item !== 3
});
console.log('length',arr.length);
console.log('arr',arr);

7.操作原型(通過在Array原型上添加方法來完成刪除)
let arr = [1,2,3,4,5,6,7,8,9];
Array.prototype.remove = function(v) {
if(isNaN(v) || v > this.length){
return false
}
for(let i = 0, j = 0; i < this.length; i++) {
if(this[i] != this[v]){
this[j++] = this[i]
}
}
this.length -= 1
}
arr.remove(2) //參數為下標
console.log('length',arr.length);
console.log('arr',arr);

轉載 https://blog.csdn.net/u010323023/article/details/52700770