The [System.String.Join](<https://msdn.microsoft.com/en-us/library/57a79xd0(v=vs.110).aspx>) method allows to concatenate all elements in a string array, using a specified separator between each element:

string[] words = {"One", "Two", "Three", "Four"};
string singleString = String.Join(",", words); // singleString = "One,Two,Three,Four"