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Lesson 16 - Abstract class, comparing and operator overloading

In the previous lesson, Type casting and object hierarchy in C# .NET, we learned about type casting and created an object hierarchy with a common ancestor in C# .NET. In today's tutorial, we're going to continue with that project.

Abstract class

An abstract class is a class whose instance does not make sense. Mainly because it is too vague, e.g. our Animal class. The point is to call on specific Animal descendants, e.g. a dog, so we won't actually instantiate the Animal class directly ever. In other words, it's better to prevent any instantiation of the class overall. To do that, we simply add the "abstract" modifier before the Animal class:

abstract class Animal
{
    . . .

The program works the same as before, but if we try to create an instance of the Animal class, we'll get an error:

// this code won't work
animals.Add(new Animal());

Other than preventing instantiation, abstract classes can do several other things


 

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This tutorial explains abstract classes in C# .NET. You'll learn about interfaces, implement your own comparing with IComparable, and overload operators.

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Article has been written for you by David Capka
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The author is a programmer, who likes web technologies and being the lead/chief article writer at ICT.social. He shares his knowledge with the community and is always looking to improve. He believes that anyone can do what they set their mind to.
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