convert comma separated string to array c#

IList<string> strings = new List<string>{"1","2","testing"};
string joined = string.Join(",", strings);

var result = string.Join(",", arr);

input.split(/[ ,]+/); //splits string using RegEx on a space OR a comma

string fruit = "Apple,Banana,Orange,Strawberry";
string[] split = fruit.Split(',');