byte overflow with unchecked

using System;/*  j a v  a  2 s . c o m*/

class MainClass
{
  static void Main(string[] args)
  {
    try
    {
      unchecked
      {
        byte b5 = 100, b6 = 200;
        byte b4 = (byte)(b5 + b6);
        Console.WriteLine("b4 = {0}", b4);
      }
    }
    catch(OverflowException e)
    { 
      Console.WriteLine(e.Message);
    }    
  }
}

using System;/* ja  va  2s .co  m*/

class MainClass
{
  static void Main(string[] args)
  {
    Console.WriteLine("System.Byte stats:");
    Console.WriteLine("Max value of byte is {0}.", byte.MaxValue);
    Console.WriteLine("Min value of byte is {0}.", byte.MinValue);

    Console.WriteLine("Catching an underflow");
    try
    {
      byte a = 9, b = 9;
      byte c = (byte)(a + b + -100);
    }
    catch(OverflowException e){Console.WriteLine(e);}

  }
}