Simple Calculator Using Switch Statement in C

This program builds a simple calculator that performs addition, subtraction, multiplication, and division based on the user’s menu choice, using a switch statement.

C Program

#include <stdio.h>

int main() {
    int choice;
    float num1, num2, result;

    printf("Enter two numbers: ");
    scanf("%f %f", &num1, &num2);

    printf("Choose an operation:\n");
    printf("1. Addition\n2. Subtraction\n3. Multiplication\n4. Division\n");
    printf("Enter your choice (1-4): ");
    scanf("%d", &choice);

    switch (choice) {
        case 1:
            result = num1 + num2;
            printf("Result: %.2f\n", result);
            break;
        case 2:
            result = num1 - num2;
            printf("Result: %.2f\n", result);
            break;
        case 3:
            result = num1 * num2;
            printf("Result: %.2f\n", result);
            break;
        case 4:
            if (num2 != 0) {
                result = num1 / num2;
                printf("Result: %.2f\n", result);
            } else {
                printf("Error: Division by zero is not allowed.\n");
            }
            break;
        default:
            printf("Invalid choice.\n");
    }

    return 0;
}

Explanation

• The user enters two numbers and picks an operation number from a menu.
• The switch statement matches choice against each case and executes only the matching block.
• break after each case prevents “fall-through” into the next case.
• Division includes a check for num2 != 0 to avoid division by zero.
• The default case handles any input outside 1–4.

Sample Output

Enter two numbers: 10 5
Choose an operation:
1. Addition
2. Subtraction
3. Multiplication
4. Division
Enter your choice (1-4): 3
Result: 50.00