数组--修改数组

1.直接修改

let arr=[1,2,3,4,5,6,7];
arr[3]=8;
console.log(arr)

//[1, 2, 3, 8, 5, 6, 7]

2.arr.splice()

let arr=[1,2,3,4,5,6];
arr.splice(2,1,8);
console.log(arr)

//[1, 2, 8, 4, 5, 6]