1 length:长度
<script> var arr = [1,2,3,4,5,6,7,8]; console.log(arr.length);//arr.length = 8; arr.length = 5;//给定数组长度; console.log(arr);//arr = [1,2,3,4,5]; delete arr[2];//删除arr[2],数组长度不变; console.log(arr);//arr = [1, 2, empty, 4, 5]; console.log(typeof(arr[2]));//undefined; console.log(arr.length); </script>
2 pop,push:方法，把数组相当于一个栈
push(x):向数组尾部压入x，并返回新数组的长度
pop():从尾部弹出一个元素，并返回弹出的元素
<script>
var arr = [1,2,3,4,5];
var number = arr.push(7);//arr.push(9) 相当于 arr[arr.length] = 7;
console.log(arr);//arr = [1,2,3,4,5,7]
console.log(number);//6
var num = arr.pop();
console.log(arr);// arr = [1,2,3,4,5]
console.log(num);//7
</script>
3 unshift 和 shift 方法，把数组相当于一个队列
unshift(x):向数组头部插入x,并返回数组长度
shift():从头部弹出一个元素，并返回弹出的元素
<script>
var arr = [1,2,3,4,5];
var number = arr.unshift(9);
console.log(arr);// arr = [9,1,2,3,4,5];
console.log(number);// 6
var num = arr.shift();
console.log(arr);// arr = [1,2,3,4,5];
console.log(num);//9
</script>
4 slice 和 splice 方法
slice(x,y):返回数组[x,y),索引位置的片段，左从0开始，右从-1开始，不影响原数组
splice(x,y,[.....]):x:删除的起始位置，y删除的个数（没有y的话，删除起始点开始所有），[...]为要插入数组的所有参数;splice方法改变原数组
<script>
var arr = [1,2,3,4,5];
console.log(arr.slice(1,3));//[2, 3]
console.log(arr);// [1,2,3,4,5]
console.log(arr.slice(1));//[2, 3, 4, 5]
console.log(arr.length);//5
console.log(arr.slice(0,-1));//[1, 2, 3, 4]
var arr1 = [1,2,3,4,5,6];
console.log(arr1.splice(1,2));//[2, 3]
console.log(arr1);//[1, 4, 5, 6]
console.log(arr1.splice(0));//[1, 4, 5, 6]
console.log(arr1);//[]
arr1 = [1,6]
console.log(arr1.splice(0,1,1,2,3,‘4‘,‘5‘));//[1]
console.log(arr1);//[1, 2, 3, "4", "5", 6]
</script>
待后续补充........
原文：https://www.cnblogs.com/Zxq-zn/p/11469824.html