Csharp/CSharp Tutorial/Data Type/unchecked

An Unchecked Block Example

using System;
public class Program
{
  public static void Main()
  {
          unchecked
          {
             // int.MaxValue equals 2147483647
             int n = int.MaxValue;
              n = n + 1 ;
             System.Console.WriteLine(n);
          }
  }
}

Mark expressions as unchecked

using System;
class MainClass
{
    public static void Main()
    {
        unchecked
        {
            byte a = 55;
            byte b = 210;
            byte c = (byte) (a + b);
        }
    }
}

Unhandled Exception: System.OverflowException: Arithmetic operation resulted in an overflow.
   at MainClass.Main()

Overflow the max value of a System.Byte

using System;
using System.Collections.Generic;
using System.Text;

  class Program
  {
    static void Main(string[] args)
    {
      byte b1 = 100;
      byte b2 = 250;
      try
      {
        byte sum = unchecked((byte)(b1 + b2));
        Console.WriteLine("sum = {0}", sum);
      }
      catch (OverflowException ex)
      {
        Console.WriteLine(ex.Message);
      }
    }
  }

unchecked marker

using System;
using System.Collections.Generic;
using System.Text;

  class Program
  {
    static void Main(string[] args)
    {
      // Declare two shorts to add.
      short numb1 = 30000, numb2 = 30000;
      // This will not throw an exception.
      unchecked
      {
        short answer = (short)Add(numb1, numb2);
        Console.WriteLine("{0} + {1} = {2}",
            numb1, numb2, answer);
      }
    }
    static int Add(int x, int y){ return x + y; }
  }