js:

var arr = str.substring(0, useranswer.length - 1).split(",");

c#:

var str="sfsdfs,sfd,fs,"   var arr =str.Split(new Char[]{','}, StringSplitOptions.RemoveEmptyEntries);//去除空数据   var arr1=str.Split(",");//保留空数据

var arr1=str.Split(new Char[]{'a','b'})