如何将单个字符串分解为字符串数组？

I have a program in which I read from a string that's formatted to have a specific look. I need the numbers which are separated by a comma (e.g. "A,B,D,R0,34,CDF"->"A","B","D","R0", "34", "CDF"). There are commas between letters that much is guaranteed I have tried to do (note: "variables" is a 2D char array, newInput is a string which is a method argumend, k and j are declared and defined as 0)I have a program in which I read from a string