What is abstract class in programming?

abstract (C++/CLI and C++/CX) The abstract keyword declares either: A type can be used as a base type, but the type itself cannot be instantiated . A type member function can be defined only in a derived type.

An Abstract method is a method without a body . The implementation of an abstract method is done by a derived class. When the derived class inherits the abstract method from the abstract class, it must override the abstract method. This requirment is enforced at compile time and is also called dynamic polymorphism.

An abstract class is a class that is declared abstract —it may or may not include abstract methods. Abstract classes cannot be instantiated, but they can be subclassed.

Abstract Data type (ADT) is a type (or class) for objects whose behaviour is defined by a set of value and a set of operations . The definition of ADT only mentions what operations are to be performed but not how these operations will be implemented.

An abstract class is a class that is designed to be specifically used as a base class . An abstract class contains at least one pure virtual function. You declare a pure virtual function by using a pure specifier ( = 0 ) in the declaration of a virtual member function in the class declaration.

The purpose of an abstract class (often referred to as an ABC) is to provide an appropriate base class from which other classes can inherit . Abstract classes cannot be used to instantiate objects and serves only as an interface. Attempting to instantiate an object of an abstract class causes a compilation error.