JS 將數字字符串轉為 數字數組

將字符串轉化為數組主要代碼：

let str = '3,4,5,6'
let arr = str.split(",").map(Number);
console.log(arr) //結果：[3,4,5,6]

 

將數字數組轉化為字符串數組

let arrs = [1, 2, 3, 4, 5, 6, 7, 8, 9];
let strArr = arrs.map(String); //結果： ['1', '2', '3', '4', '5', '6', '7', '8', '9']
let newStr = strArr.join(',');
console.log(newStr)//結果為：1,2,3,4,5,6,7,8,9