You can use optional parameter . you can this by this way class Program { static void Main(string[] args) { Console.WriteLine(Sum(1, 2, 3).ToString()); Console.WriteLine(Sum( 2, 3).ToString()); Console.ReadLine(); } static int Sum(params int[] li) { int sum=0; for ( int i = 0 ; i < li.Length ; i++ ) { sum+=li[i]; } return sum; } }