List to CSV

List of Int to CSV 

List<int> list = new List<int>() {1,2,3,4,5};
Console.WriteLine(list.Select(f => f.ToString()).Aggregate((x, y) => x+","+y));

Output 

1,2,3,4,5 

 List of string to CSV using string.join

 List list = new List() {"1","2","3","4","5"};
 string joined =  string.Join("\",\"", list) ; 

Output  1,2,3,4,5  

 List of string to CSV using string.join  and string.Format

List list = new List() {"1","2","3","4","5"};
 string joined =  string.Format("\"{0}\"", string.Join("\",\"", list)); 

 Output  "1","2","3","4","5"