How to Take Operator as Input in C++?

Operators are symbols that specify some kind of operation. In C++, we sometimes need to take operators as user input mainly to perform mathematical operations. In this article, we will learn how to take operators as user input in C++.

Operators as Input in C++

To take operators (like +,-,*,/ etc) as user input, we can use a char datatype to read the operator as a character using cin and then validate whether the entered operator is valid or not using a switch or conditional statements.

C++ Program to Take Operator as Input

The below example demonstrates how we can take the operator as user input, validate it, and perform mathematical calculations.

C++

// C++ program to take operator as input
#include <iostream>

using namespace std;

int main()
{
    // Declaring variables to store two numbers and the
    // operator
    double num1, num2;
    char op;

    // Get the first number from the user
    cout << "Enter the first number: ";
    cin >> num1;

    // Get the second number from the user
    cout << "Enter the second number: ";
    cin >> num2;

    // Get the arithmetic operator from the user
    cout << "Enter the arithmetic operator (+, -, *, /): ";
    cin >> op;

    // Declare a variable to store the result of the
    // operation
    double result;

    // Use a switch statement to perform the operation based
    // on the operator
    switch (op) {
    case '+':
        result = num1 + num2;
        break;
    case '-':
        result = num1 - num2;
        break;
    case '*':
        result = num1 * num2;
        break;
    case '/':
        // Check if the second number is not zero before
        // performing division
        if (num2 != 0) {
            result = num1 / num2;
        }
        else {
            cout << "Error: Division by zero." << endl;
            return 1; // Return an error code
        }
        break;
    default:
        cout << "Error: Invalid operator." << endl;
        return 1; // Return an error code
    }

    // Display the result of the operation
    cout << "Result: " << result << endl;

    return 0;
}

Output

Enter the first number: 8   
Enter the second number: 2
Enter the arithmetic operator (+, -, *, /): /
Result: 4