JS - 字符串转换成数组，数组转换成字符串

1.字符串转换成数组：

var arr = "1, 2, 3, 4, 5, 6";
arr.split(","); // ["1","2","3","4","5","6"]

2.数组转换成字符串：

var str = [1, 2, 3, 4];
str.join(","); // "1, 2, 3, 4"