Using checked and unchecked with statement blocks

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Using checked and unchecked with statement blocks. 
 
using System; 
 
public class CheckedBlocks {  
  public static void Main() {  
    byte a, b; 
    byte result; 
 
    a = 127; 
    b = 127; 
  
    try {  
      unchecked { 
        a = 127; 
        b = 127; 
        result = unchecked((byte)(a * b)); 
        Console.WriteLine("Unchecked result: " + result); 
 
        a = 125; 
        b = 5; 
        result = unchecked((byte)(a * b)); 
        Console.WriteLine("Unchecked result: " + result); 
      } 
 
      checked { 
        a = 2; 
        b = 7; 
        result = checked((byte)(a * b)); // this is OK 
        Console.WriteLine("Checked result: " + result); 
 
        a = 127; 
        b = 127; 
        result = checked((byte)(a * b)); // this causes exception 
        Console.WriteLine("Checked result: " + result); // won't execute 
      } 
    }  
    catch (OverflowException exc) {  
      // catch the exception  
      Console.WriteLine(exc); 
    }  
  }  
}