interface in c 2b 2b

1#include <iostream>
2#include  <string>
3//Pure virtual function or inteface allows us to define a function in a base class that doesn't have an implementation or definition in the base class and force sub classes to implement that function
4//Pure virtual function is also called an interface in other languages
5class Entity {
6public:
7	//virtual std::string GetName() { return "Entity"; }//This is a function that is just virtual .Overriding this function in sub class is optional we can instantiate subcllass without overriding  or implementing this function
8	
9	//Below is an example a Pure Virtual Function
10	//It is an unimplemented function ant it forces the  sub class to implement it and define it
11	//You will not be able to instantiate sub class without implementing or defining the function in sub class
12	virtual std::string GetName() = 0; 
13  //the pure virtual function must have virtual written at the beginning and =0 at the end
14 //This function cannot contain any definition in base class,it is just a declaration
15};
16class Player :public Entity {
17	std::string m_name;
18
19public:
20	Player(const std::string& name)
21		:m_name(name)
22	{};
23	void Print() { std::cout << "This is Sub class" << std::endl; };
24	std::string GetName()override { return m_name; };//Pure virtual functions is implemented here in this sub class
25};
26
27int main()
28{
29	//Entity a;//We can't do this because class Entity contains function that is unimplemented
30	Player x("Jacob");//This will work because we have implemented or defined the function in this sub class
31	std::cin.get();
32}

1class IDemo
2{
3    public:
4        virtual ~IDemo() {}
5        virtual void OverrideMe() = 0;
6};
7
8class Child : public IDemo
9{
10    public:
11        virtual void OverrideMe()
12        {
13            //do stuff
14        }
15};
16

1class IDemo
2{
3    public:
4        virtual ~IDemo() {}
5        virtual void OverrideMe() = 0;
6};
7
8class Parent
9{
10    public:
11        virtual ~Parent();
12};
13
14class Child : public Parent, public IDemo
15{
16    public:
17        virtual void OverrideMe()
18        {
19            //do stuff
20        }
21};
22