C Virtual Function

1. What is a virtual function in C?
2. Does C have virtual functions?
3. What are virtual functions write an example?
4. Why virtual function is used in C++?
5. What is pure virtual function?
6. What is virtual base class with example?
7. What is difference between virtual and pure virtual function?
8. What is the purpose of virtual function?
9. What is a pure virtual function C++?
10. What is pure virtual function example?
11. What is virtual and friend in C++?
12. Which keyword is used to declare virtual functions?

What is a virtual function in C?

A virtual function is a member function which is declared within a base class and is re-defined(Overriden) by a derived class. ... Virtual functions ensure that the correct function is called for an object, regardless of the type of reference (or pointer) used for function call.

Does C have virtual functions?

Although C doesn't provide native support for virtual functions, you can emulate virtual functions in C if you attend to all the details.

What are virtual functions write an example?

Example 2: C++ virtual Function Demonstration

• When print(animal1) is called, the pointer points to an Animal object. So, the virtual function in Animal class is executed inside of print() .
• When print(dog1) is called, the pointer points to a Dog object. ...
• When print(cat1) is called, the pointer points to a Cat object.

Why virtual function is used in C++?

A C++ virtual function is a member function in the base class that you redefine in a derived class. It is used to tell the compiler to perform dynamic linkage or late binding on the function. ... There is a necessity to use the single pointer to refer to all the objects of the different classes.

What is pure virtual function?

A pure virtual function or pure virtual method is a virtual function that is required to be implemented by a derived class if the derived class is not abstract. Classes containing pure virtual methods are termed "abstract" and they cannot be instantiated directly.

What is virtual base class with example?

Virtual base classes are used in virtual inheritance in a way of preventing multiple “instances” of a given class appearing in an inheritance hierarchy when using multiple inheritances.

What is difference between virtual and pure virtual function?

A virtual function is a member function of base class which can be redefined by derived class. A pure virtual function is a member function of base class whose only declaration is provided in base class and should be defined in derived class otherwise derived class also becomes abstract.

What is the purpose of virtual function?

A virtual function is a member function that you expect to be redefined in derived classes. When you refer to a derived class object using a pointer or a reference to the base class, you can call a virtual function for that object and execute the derived class's version of the function.

What is a pure virtual function C++?

A pure virtual function is a virtual function in C++ for which we need not to write any function definition and only we have to declare it. It is declared by assigning 0 in the declaration. ... If an Abstract Class has derived class, they must implement all pure virtual functions, or else they will become Abstract too.

What is pure virtual function example?

A pure virtual function doesn't have the function body and it must end with = 0 . For example, class Shape public: // creating a pure virtual function virtual void calculateArea() = 0; ; Note: The = 0 syntax doesn't mean we are assigning 0 to the function. It's just the way we define pure virtual functions.

What is virtual and friend in C++?

It is a base class function that can be overridden by a derived class. ... It is declared outside the class scope. It is declared using the 'friend' keyword. It is declared within the base class and is usually redefined by a derived class. It is declared using a 'virtual' keyword.

Which keyword is used to declare virtual functions?

Which keyword is used to declare virtual functions? Explanation: The virtual keyword is used to declare virtual functions. Anonymous keyword is used with classes and have a different meaning. The virtual functions are used to call the intended function of the derived class.