C++ Interfaces

by Online Tutorials Library July 14, 2022

Interfaces in C++ (Abstract Classes)

Abstract classes are the way to achieve abstraction in C++. Abstraction in C++ is the process to hide the internal details and showing functionality only. Abstraction can be achieved by two ways:

Abstract class
Interface

Abstract class and interface both can have abstract methods which are necessary for abstraction.

C++ Abstract class

In C++ class is made abstract by declaring at least one of its functions as <>strong>pure virtual function. A pure virtual function is specified by placing “= 0” in its declaration. Its implementation must be provided by derived classes.

Let’s see an example of abstract class in C++ which has one abstract method draw(). Its implementation is provided by derived classes: Rectangle and Circle. Both classes have different implementation.

 #include <iostream> using namespace std;  class Shape   {       public:      virtual void draw()=0;   };    class Rectangle : Shape   {       public:      void draw()       {           cout < <“drawing rectangle…” < <endl;       }   };   class Circle : Shape   {       public:      void draw()       {           cout <<“drawing circle…” < <endl;       }   };   int main( ) {     Rectangle rec;     Circle cir;     rec.draw();       cir.draw();     return 0; } 

Output:

drawing rectangle... drawing circle...

Next TopicData Abstraction in C++

C++ Interfaces

Interfaces in C++ (Abstract Classes)

C++ Abstract class

C++ try-catch

Box-shadow CSS

You may also like