concat:拼接數(shù)組,不改變原數(shù)組
let arr1 = [1,2,3]
let arr2 = [8,5,3]
let arr3 = arr2.concat(arr1)
console.log(arr1)
console.log(arr2)
console.log(arr3)

image.png
concat:拼接數(shù)組,不改變原數(shù)組
let arr1 = [1,2,3]
let arr2 = [8,5,3]
let arr3 = arr2.concat(arr1)
console.log(arr1)
console.log(arr2)
console.log(arr3)