Confused with polymorphism written in C#

Question

Hi my workmate just told me that it is possible to achieve polymorphism by hiding a base class method and implementing another method with the same signature in the derive class, Is this true and how could this be needed in real life situations?

The C# Programming Guide on MSDN has a [whole section](http://msdn.microsoft.com/en-us/library/ms173152%28v=vs.100%29.aspx) on polymorphism and it's uses, including Hiding Base Class Members with New Members among other topics. — raveturned, May 02 '12 at 14:49
I'm not sure whats unclear. Its obvious that this question is about confusion on C#s hiding "feature" and actual polymorphism, and there's a question that addresses this confusion below. — Andy, May 02 '12 at 14:50

score 2 · Accepted Answer · edited May 23 '17 at 12:20

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I guess your friend was talking about shadowing. It's not true polymorphism and should be avoided Difference between shadowing and overriding in C#?

edited May 23 '17 at 12:20

Community

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answered May 02 '12 at 14:46

empi

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Shadowing is just the VB word for what C# calls Hiding. – H H May 02 '12 at 14:50
@HenkHolterman - thanks, didn't know that. Shadowing sounds much better. – empi May 02 '12 at 14:53

score 0 · Answer 2 · answered May 02 '12 at 14:49

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That is pretty much anti-polymorphism. The 'real' method for the object should be executed whenever called, regardless of the type of the variable, for polymorphism; you expect derived.Method() to be called whether you call it on a variable of type base or type derived, if the object in question is of type derived.

Hiding breaks that expectation.

answered May 02 '12 at 14:49

Andrew Barber

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+1 for the informative answer thanks :) – May 02 '12 at 14:52

Confused with polymorphism written in C#

2 Answers2