Nullable types

A new language construct as of the .NET 2.0 Framework is Nullable types. Basically, it allows one to extend a Value Type (such as int, bool), and make it nullable.

Here's a small sample class I wrote to experiment with using Nullable Types.

namespace Project
{
    public class DataTest
    {
        // The syntax T? (in C#) is shorthand for System.Nullable<T>, where T is a value type. The two forms are interchangeable.
        private int? age = null;
        private System.Nullable<system.int32> weight = null;

        public int? Age
        {
            get { return age; }
            set { age = value; }
        }

        public int? Weight
        {
            get { return weight; }
            set { weight = value; }
        }

        public DataTest()
        {}

        public DataTest(int? myAge, int? myWeight)
        {
            Age = myAge;
            Weight = myWeight;
        }

        /// 

        /// Return String displaying age and weight
        /// 
        /// 
        public override string ToString()
        {
            if (Age.HasValue && Weight.HasValue)
            {
                return "Your age is: " + Age.Value + ", and your weight is: " + Weight.Value;
            }
            else
            {
                return "No age or weight entered";
            }
        }
    }
}

The following is a good reference for Nullable Types: Introduction to .Net Framework 2.0 Nullable Types.