List<T> -> String으로 변환

List<string> names = new List<string>() { "John", "Anna", "Monica" };
var result = String.Join(", ", names.ToArray());


var combined = String.Join(",", new String[]{"a","b"});
// a,b


List<string> names = new List<string>() { "John", "Anna", "Monica" };
var result = String.Join(", ", names.ToArray());


using System.Linq
string.Join(",", people.Select(x => x.surname))