ArgumentException is thrown when one of the arguments provided to a method is not valid.
using System; public sealed class App { static void Main() { Console.WriteLine("10 divided by 2 is {0}", DivideByTwo(10)); try { Console.WriteLine("7 divided by 2 is {0}", DivideByTwo(7)); } catch (ArgumentException) { Console.WriteLine("7 is not divided by 2 integrally."); } } static int DivideByTwo(int num) { if ((num & 1) == 1) throw new ArgumentException("Number must be even", "num"); return num / 2; } }