Abstract Classes and Methods
Explore how abstract classes and methods work in C# to promote abstraction and flexible inheritance. This lesson explains key rules, syntax, and practical use through a vending machine example, helping you grasp how to define and implement abstract members in your object-oriented projects.
We'll cover the following...
Abstract Methods
An abstract method is declared using the
abstractkeyword and does not have a body/ implementation.
There are certain rules we should follow when working with abstract methods. Let’s have a look at these rules.
Rules to be Followed
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In contrast to a non-abstract/normal C# method, an abstract method does not have a body/definition, i.e., it only has a declaration or method signature.
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An abstract method can be declared inside an abstract class or an interface only, more on these later.
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To contain any abstract method in its implementation, a class has to be declared as an abstract class. Non-abstract classes cannot have abstract methods.
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An abstract method cannot be declared with the
privateorsealedmodifier as it has to be implemented in some other class. -
Abstract methods are implicitly
virtualso we cannot use the keywordvirtualin their declaration.
Just like abstract methods, an abstract ...