how to join array indexes with comma in c# code example

Example: how to join array indexes with comma in c#

List<string> testList= new List<string>();
testList.Add("Apple"); // Add string 1
testList.Add("Banana"); // 2
testList.Add("Mango"); // 3
testList.Add("Blue Berry"); // 4
testList.Add("Water Melon"); // 5

string JoinDataString = string.Join(",", testList.ToArray());