C# Tips & Tricks #33 – Why doesn’t this cause an Exception ?

This blog post explain the usage of the Checked Block in .NET and how you can use them in Visual Studio.

I was trying to run the below code snippet in Visual Studio 2010 .

     int Number1 = 320000;

     int Number2 = 320000;

     int Number3 = Number1 * Number2 ;

     MessageBox.Show(Number3.ToString());

The code resulted in the value – 797966336 without being showing the error or the correct value .

Just found that If you want an exception to be raised on this occassion , then use the following 2 options as below .

1. Checked Block

Checked
{
      int Number1 = 320000;

      int Number2 = 320000;

      int Number3 = Number1  * Number2 ;

      MessageBox.Show(Number3.ToString());
}

2. Enable the checked compiler option in Visual Studio Project Properties

To set the compiler option in the Visual Studio 2010 .

1. Right Click on the Project and open Properties.

2. Click the Build Property Tab page

3. Click the Advanced Button near the Output.

4.Check the Property “Check for Arithmetic Overflow/Underflow” and Click ok .

Now run the same code again , you should be able to raise an exception

OverFlow Exception was unhandled .

Arithmetic operation resulted in an overflow.