js 数组开头和结尾添加删除和删除元素

1:push为在最后添加元素

mounted() {
    
    
			var arr = [
				{
    
    
					name:"q",
					age:1
				},
				{
    
    
					name:"w",
					age:2
				},
				{
    
    
					name:"e",
					age:3
				}
			]
			arr.push(
				{
    
    
					name:"r",
					age:4
				}
			)
			console.log(arr)
		},

结果为：

2:unshift为在最前面添加元素

mounted() {
    
    
			var arr = [
				{
    
    
					name:"q",
					age:1
				},
				{
    
    
					name:"w",
					age:2
				},
				{
    
    
					name:"e",
					age:3
				}
			]
			arr.unshift(
				{
    
    
					name:"r",
					age:422
				}
			)
			console.log(arr)
		},

结果为：

3:pop为在最后删除元素

mounted() {
    
    
			var arr = [
				{
    
    
					name:"q",
					age:1
				},
				{
    
    
					name:"w",
					age:2
				},
				{
    
    
					name:"e",
					age:3
				}
			]
			arr.pop();
			console.log(arr)
		},

结果为：

4:shift为在最前面删除元素

mounted() {
    
    
			var arr = [
				{
    
    
					name:"q",
					age:1
				},
				{
    
    
					name:"w",
					age:2
				},
				{
    
    
					name:"e",
					age:3
				}
			]
			arr.shift();
			console.log(arr)
		},

结果为：