数组 slice 和 splice 区别

数组 slice 和 splice 区别

• 功能区别 （slice - 切片，splice - 剪接）
• 参数和返回值
• 是否是纯函数

slice 纯函数

const arr = [10, 20, 30, 40, 50]

const arr1 = arr.slice()
console.log(arr1) // [10, 20, 30, 40, 50]

const arr2 = arr.slice(1, 4)
console.log(arr2) // [20, 30, 40]

const arr3 = arr.slice(2)
console.log(arr3) // [30, 40, 50]

const arr4 = arr.slice(-3)
console.log(arr4) // [30, 40, 50]

splice 非纯函数

const arr = [10, 20, 30, 40, 50]

// splice 非纯函数
const spliceRes = arr.splice(1, 2, 'a', 'b', 'c')
console.log(spliceRes, arr) //[20,30] [10, 'a', 'b', 'c', 40, 50]

const spliceRes1 = arr.splice(1, 2)
console.log(spliceRes1, arr)//[20,30] [10, 40, 50]

const spliceRes2 = arr.splice(1, 0, 'a', 'b', 'c')
console.log(spliceRes2, arr)//[] [10, "a", "b", "c", 20, 30, 40, 50]