#753 – Implicitly Upcast to a Base Class Reference

You can convert a reference to a child class to a reference to its base class using an upcast.  (“Up” indicates that you’re moving up the inheritance tree).  You can do this upcast implicitly, meaning that you don’t need a cast operator that indicates the target type.

For example, assume that Terrier is a subclass of Dog.  If we have a reference to a Terrier object, we can assign that reference to a variable that is a reference to a Dog.

            Terrier t = new Terrier("Jack", Terrier.GrowlFactor.Severe);

            // Implicit upcast - aDog now refers to Jack the Terrier
            Dog aDog = t;

After the upcast, we have a reference of type Dog that refers to an instance of a Terrier.

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About Sean
Software developer in the Twin Cities area, passionate about .NET technologies. Equally passionate about my own personal projects related to family history and preservation of family stories and photos.

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