[Examples – Difference] Early binding and Late Binding in C++

Difference between Early binding and late binging

Early binding	late binging
Order of Execution: 1^st(Early binding) then 2^nd (late binging)
static binging	Dynamic Binding
Compile-time	Run time polymorphism
Matching of a function call with function definition is performed at compiler time.	Matching of a function call with function definition is performed at run time.
Full information about function calling and matching with function definition is visible to the compiler during compile time	Full information about function calling and matching with function definition is not visible to the compiler during compile time but it’s visible during run time.
More efficient: because the compiler already has knowledge that what code will execute	More flexible:
Fast execution	Slow execution
Examples: Function overloading and operator overloading	Examples: Virtual functions

Example of Early binding in C++

#include <iostream>  
using namespace std;  
class A  
{  
   int n1=33;  
    public:  
     void display()  
    {  
        std::cout << "Value of n1 is : " << n1<<std::endl;  
    }  
};  
class B: public A  
{  
    int n2 = 44;  
    public:  
    void display()  
    {  
        std::cout << "Value of n2 is : " <<n2<< std::endl;  
    }  
};  
int main()  
{  
    A *object1;  
    B object2;  
    object1 = &object2;  
   object1->display();  
    return 0;  
}

Output

Value of n1 is : 33

Example of Late binding in C++

Late binding can be implemented by making a function as a virtual function.

C++ program to demonstrate working of virtual function

#include <iostream>  
using namespace std;  
class A  
{  
   int n1=33;  
    public:  
    virtual void display()  
    {  
        std::cout << "Value of n1 is : " << n1<<std::endl;  
    }  
};  
class B: public A  
{  
    int n2 = 44;  
    public:  
    void display()  
    {  
        std::cout << "Value of n2 is : " <<n2<< std::endl;  
    }  
};  
int main()  
{  
    A *object1;  
    B object2;  
    object1 = &object2;  
   object1->display();  
    return 0;  
}

Output

Value of n2 is : 44