C# Value Keyword

The contextual keyword value is used in the set accessor in ordinary property declarations. It is similar to an input parameter on a method. The word value references the value that client code is attempting to assign to the property. In the following example, MyDerivedClass has a property called Name that uses the value parameter to assign a new string to the backing field name. From the point of view of client code, the operation is written as a simple assignment.

The MSDN reference can be found here.

Code Example

 class MyBaseClass

        {

            // virtual auto-implemented property. Overrides can only

            // provide specialized behavior if they implement get and set accessors.

            public virtual string Name { get; set; }

            // ordinary virtual property with backing field

            private int num;

            public virtual int Number

            {

                get { return num; }

                set { num = value; }

            }

        }

        class MyDerivedClass : MyBaseClass

        {

            private string name;

            // Override auto-implemented property with ordinary property

            // to provide specialized accessor behavior.

            public override string Name

            {

                get

                {

                    return name;

                }

                set

                {

                    if (value != String.Empty)

                    {

                        name = value;

                    }

                    else

                    {

                        name = "Unknown";

                    }

                }

            }

        }


As seen in the above code, the value keyword gives us access to the implied value that is sent when the Name property is assigned a value. This allows us to do error handling before we assign the value to our name field.