7.27.1.Using Abstract Classes |
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- An abstract method is created by specifying the abstract type modifier.
- An abstract method contains no body.
- An abstract method is not implemented by the base class.
- An abstract method is automatically virtual.
- A derived class must override it.
- The abstract modifier cannot be applied to static methods.
- Properties can also be abstract.
- A class containing abstract methods must be declared as abstract with the abstract specifier.
- There can be no objects of an abstract class.
- If a derived class doesn't implement all of the abstract methods in the base class, then the derived class must also be specified as abstract.
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To declare an abstract method, use this general form: |
abstract type name(parameter-list);
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