How to Take Operator as Input in C?

Last Updated : 12 Jun, 2024

In C, an operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations. We may need to take operator as an input in some cases. In this article, we will learn how to take an operator as input in C.

Get Input Operator in C

To take an operator as input in C, we can use the we can use any input function (scanf(), fgets(), etc) to take that operator as a character. We can them use any conditional statement (but switch statement is preferred in such cases) to find out which operator is used.

C Program to Take Operator as Input

The below example demonstrates the use of scanf function to take an operator as input in C.

#include <stdio.h>

int main()
{
    char operator;
    double num1, num2, result;

    // Prompt the user to enter an operator
    printf("Enter an operator (+, -, *, /): ");
    scanf(" %c", &operator);

    // Prompt the user to enter two operands
    printf("Enter two numbers: ");
    scanf("%lf %lf", &num1, &num2);

    // Perform the operation based on the operator input
    switch (operator) {
    case '+':
        result = num1 + num2;
        printf("%.2lf + %.2lf = %.2lf\n", num1, num2,
               result);
        break;
    case '-':
        result = num1 - num2;
        printf("%.2lf - %.2lf = %.2lf\n", num1, num2,
               result);
        break;
    case '*':
        result = num1 * num2;
        printf("%.2lf * %.2lf = %.2lf\n", num1, num2,
               result);
        break;
    case '/':
        if (num2 != 0) {
            result = num1 / num2;
            printf("%.2lf / %.2lf = %.2lf\n", num1, num2,
                   result);
        }
        else {
            printf("Error: Division by zero is not "
                   "allowed.\n");
        }
        break;
    default:
        printf("Error: Invalid operator.\n");
        break;
    }

    return 0;
}

Output

Enter an operator (+, -, *, /): +
Enter two numbers: 10
20
10.00 + 20.00 = 30.00

We can define more operators in the switch statement and even include the check for binary, unary and ternary operator and then ask the operands accordingly.