C++ Program to Make a Simple Calculator

A simple calculator is a device used to perform basic arithmetic operations such as addition, subtraction, multiplication, and division. It makes arithmetic calculations easier and faster. In this article, we will learn how to code a simple calculator using C++.

Algorithm to Make a Simple Calculator

• Initialize two float variables num1 and num2 to take two operands as input.
• Initialize a char variable op to take the operator as input.
• Start the switch statement with op as the expression of the switch statement.
• Now, create cases for different arithmetic operations.
  • ‘+’ for addition
  • ‘-‘ for subtraction
  • ‘*’ for multiplication
  • ‘/’ for division
  • Default case for the case when the entered operator is not one of the above operators.
• The operation will be performed based on the operator entered as the input.

C++ Program to Implement a Simple Calculator

Below is the C++ program to make a simple calculator using switch and break statements:

C++

// C++ program to create calculator using
// switch statement
#include <iostream>
using namespace std;

// Driver code
int main()
{
    char op;
    float num1, num2;

    // It allows user to enter operator
    // i.e. +, -, *, /
    cin >> op;

    // It allow user to enter the operands
    cin >> num1 >> num2;

    // Switch statement begins
    switch (op) {
    // If user enter +
    case '+':
        cout << num1 + num2;
        break;

    // If user enter -
    case '-':
        cout << num1 - num2;
        break;

    // If user enter *
    case '*':
        cout << num1 * num2;
        break;

    // If user enter /
    case '/':
        cout << num1 / num2;
        break;

    // If the operator is other than +, -, * or /,
    // error message will display
    default:
        cout << "Error! operator is not correct";
    }
    // switch statement ends

    return 0;
}

Input

+
2
2

Output

4

Complexity Analysis

Time Complexity: O(1)
Auxiliary Space: O(1)