What is pure virtual functions? Write down the rules used for pure virtual function.

What is pure virtual functions? Write down the rules used for pure virtual function.
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1 Answer

Answer :

A pure virtual function is a function which is declared in a base class and which does not have definition relative to the base class. In such cases, the compiler requires each derived class to either defined in a derived class or is re-declared as pure virtual function. A pure virtual function in base class only serves as a placeholder. Such functions are also called as ‟do-nothing‟ functions.

Ex:-

class ABC

{

public:

virtual void display( )=0;

};

Rules:-

1. A pure virtual function in base class does not have definition relative to base class.

2. A class containing pure virtual functions cannot be used to declare any objects of its own.

 
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