🌦🌦数组删除某个下标对象

let dataSource = ["a", "b", "c"]
let newDataSource = dataSource.splice(2, 1);
console.log(newDataSource) // ["c"]
console.log(dataSource) //  ["a", "b"]

let dataSource = ["a", "b", "c"]
for (let i = 0; i < dataSource.length; i ++) {
  dataSource.splice(i, 1)
  console.log(dataSource) // ["b", "c"],  ["c"] , []
  i = i - 1 // 原来的元素被删掉需要往前一位
}

let dataSource = ["a", "b", "c"]
let newDataSource = dataSource.slice(1,2);
console.log(newDataSource) // ["b"]
console.log(dataSource) //  ["a", "b", "c"]