我要评论通过扩展运算符和fliter来达到不改变原数组的情况下，添加和删除元素
1、添加元素
var numList = [1, 2, 3, 4, 5, 6, 7, 8, 9]
// 第一种方案
function add (newList, num) {
return [...newList, num]
}
// 第二种方案
function add (arr, num) {
const newArr = [...arr] // copy arr to then new array
newArr.push(num) // Add num parameter to the end of the new array.
return newArr // Return the new array.
}
// 输出
var newNumList = add(numList, 10)
console.log('newNumList', newNumList) // newNumList , [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
console.log('numList', numList) // numList ,[1, 2, 3, 4, 5, 6, 7, 8, 9] 2、删除元素
var numList = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
// 第一种方案
function remove (list, num) {
return list.filter(e => e !== num)
}
// 第二种方案
function remove (arr, num) {
const newArr = [...arr] // Copy the numlist array to a new array.
if (newArr.indexOf(num) >= 0) {
newArr.splice(newArr.indexOf(num), 1) // Remove the given paramater from the new array.
return newArr // Return the new array.
}
}
// 输出
var removeNumList = remove(numList, 10)
console.log('newNumList', removeNumList) // newNumList , [1, 2, 3, 4, 5, 6, 7, 8, 9]
console.log('numList', numList) // numList ,[1, 2, 3, 4, 5, 6, 7, 8, 9,10] 本文地址：https://blog.csdn.net/betterliumm/article/details/107858371
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