Calculator using Classes in C++

Last Updated : 23 Jul, 2022

Implementing a calculator in C++ using the concept of the classes.

Functions:

Addition of two numbers.
Difference between two numbers.
Product of two numbers.
Division of two numbers.

Approach:

Declare local variables a, b for two numeric values.
Enter the Choice.
Takes two numbers, a and b.
do-while jump to an operator selected by the user.
Display the operation result.
Exit

Examples:

Input: a = 5, b = 10, choice = 1
Output: Sum is 15

Input: a = 10, b = 4, choice = 3
Output: Product is 40

Below is the C++ program implementation of the above approach-

C++

// C++ program to implement 
// the above approach
#include <iostream>
#include <math.h>
using namespace std;

// Class calculator 
class Calculator
{
   float a, b;
public:
  
    // Function to take input
    // from user
    void result() 
    {
        cout << "Enter First Number: ";    
        cin >> a;
        cout << "Enter Second Number: ";   
        cin >> b;
    }
  
    // Function to add two numbers
    float add() 
    {
        return a + b;
    }
  
    // Function to subtract two numbers
    float sub() 
    {
        return a - b;
    }
  
    // Function to multiply two numbers
    float mul() 
    {
        return a * b;
    }
  
    // Function to divide two numbers
    float div() 
    {
        if (b == 0) 
        {
            cout << "Division By Zero" << 
                     endl;
            return INFINITY;
        }
        else 
        {
            return a / b;
        }
    }
};

// Driver code
int main() 
{
    int ch;
    Calculator c; 
    cout << "Enter 1 to Add 2 Numbers" << 
            "\nEnter 2 to Subtract 2 Numbers" << 
            "\nEnter 3 to Multiply 2 Numbers" << 
            "\nEnter 4 to Divide 2 Numbers" << 
            "\nEnter 0 To Exit";
        
    do 
    {
        cout << "\nEnter Choice: ";
        cin >> ch;
        switch (ch)
        {
        case 1:
            
            // result function invoked
            c.result();     
            
            // add function to calculate sum
            cout << "Result: " << 
                     c.add() << endl; 
            break;
        case 2:
            
            // sub function to calculate 
            // difference
            c.result();
            cout << "Result: " << 
                     c.sub() << endl; 
            break;
        case 3:
            c.result();
            
            // mul function to calculate product
            cout << "Result: " << 
                     c.mul() << endl; 
            break;
        case 4:
            c.result();
            
            // div function to calculate division
            cout << "Result: " << 
                     c.div() << endl; 
            break;
        }
        
    } while (ch >= 1 && ch <= 4);
    
    return 0;
}