Checked Keyword

2008-03-04T22:25:00Z

I recently discovered the “checked” keyword which is used to throw an exception when arithmetic overflow occurs. This is important as .net automatically narrows data types which could lead to overflow problems. The following example shows how this situation could arise:

class Program
{
    static void Main(string[] args)
    {
       int value1 = 100000;
       int value2 = 200000;

short value3 = (short)Add(value1, value2);

Console.WriteLine(value3);
}

static int Add(int x, int y) {
return x + y; }
}

Note that this code will compile cleanly at appears to be valid. However, casting the Add result to a short results in an overflow condition that will not be detected at run-time. This can be trapped by using the checked keyword thus:

class Program
{
    static void Main(string[] args)
    {
        int value1 = 100000;
        int value2 = 200000;

short value3 = checked((short)Add(value1, value2));

Console.WriteLine(value3);
}

static int Add(int x, int y) {
return x + y; }
}

NET Framework 3.0

2006-10-03T10:05:00Z

I have had a couple of customers ask the question. What is in the .NET Framework 3.0 and why the off pattern release. Recently Microsoft renamed the WinFX to .NET Framework 3.0 this will be released in the Office/Vista timframe. We are currently at the RC1 release located at: .NET Framework 3.0

The included features of the NETFR3 are:

Windows Communication Foundation
Windows Presentation Foundation
Windows Workflow Foundation (Dub F)
Windows CardSpace

David Gardner's Snippets

Checked Keyword

NET Framework 3.0