C++ Program to Perform operator overloading on unary operator Increment ++ with no return type

In this C++ program, the increment ++ operator is overloaded. i.e., increase the value of a data member by 1 if the ++ operator operates on an object.

What is operator overloading?

Polymorphism: Polymorphism (or operator overloading) is a concept in object-oriented programming that allows one method or operator to be used differently for different operations. In C++, we can make one operator works differently on different objects or classes, or structures which is called operator overloading.
 

Operator overloading in C++

Create a class check and declare a variable i in private. The class members declared as private can be accessed only by the member functions inside the class. A constructor check () is created in public and set the value of variable i to 0. Here, we are using the operator ++ to work in a way that increases the value of the variable by 1. Now we make a function to display the value of the variable.

Within the main function body, create an object obj for the class check. Display the initial value of the data member i for object obj. Invoke the operator function void operator ++( ). Perform the operation ++obj; Display the value of the data member i after the operation using obj.Display();

Algorithm

Step 1:  Call the header file iostream.

Step 2: Use the namespace std.

Step 3: Create a class check with a private variable i

Step 4: create a constructor check( ); set the value of i to 0

Step 5: Define the function for operator overloading 

Step 6: Define function display for displaying the data member.

Step 7: call the function main

Step 8: create an object obj for the class check

Step 9: Display the value of the data member by accessing the function with the object

Step 10: call the function for operator overloading

Step 11: Display the data member after the operation by calling the display function.

Step 12: Exit 

                                          #include <iostream>
using namespace std;

class Check
{
    private:
       int i;
    public:
       Check(): i(0) {  }
       void operator ++() 
          { ++i; }
       void Display() 
          { cout << "i=" << i << endl; }
};

int main()
{
    Check obj;

    // Displays the value of data member i for object obj
    obj.Display();

    // Invokes operator function void operator ++( )
    ++obj; 
  
    // Displays the value of data member i for object obj
    obj.Display();

    return 0;
}
                                      

i=0
i=1