数组转字符串，字符串转数组

数组转字符串

var a=[1,2,3,4,5];  /数组
var b=a.join(",");
console.log(b) //字符串  

字符串转数组

var a="1,2,3,4,5";
var b=a.split(",");
console.log(b)//数组