The calculator prompts users to enter two numbers and select an operation. It then performs the calculation and displays the result. The program is designed with clarity in mind, making it an excellent resource for beginners learning C programming concepts such as input/output handling, conditional statements, loops, and basic arithmetic logic.

Calculator.c

#include <stdio.h>

int main() 
{
	
    int a, b, opt, res; 
	// declaring variables
    printf("Welcome To Switch Case Calculator\n"); 
	// Welcome command / Message
    printf("Enter first number: ");
    scanf("%d", &a); 
	// asking user for first number (first Input)
    printf("Enter second number: ");
    scanf("%d", &b); 
	// asking user for second number (Second Input)

    printf("Arithmetic Operations: \n");
    printf("1. Addition\n");
    printf("2. Subtraction\n");
    printf("3. Multiplication\n");
    printf("4. Division\n");
    printf("5. Modulus Division\n"); 
	// Setting options
	
    printf("Enter your choice: ");
    scanf("%d", &opt);

    switch(opt)
	{ 
        case 1:
            res = a + b;
            printf("Addition: %d\n", res);
            break;
            
        case 2:
            res = a - b;
            printf("Subtraction: %d\n", res);
            break;
            
        case 3:
            res = a * b;
            printf("Multiplication: %d\n", res);
            break;
            
        case 4:
            if(b != 0) {
                res = a / b;
                printf("Division: %d\n", res);
            } else {
                printf("Error: Division by zero!\n");
            }
            break;
            
        case 5:
            if(b != 0) {
                res = a % b;
                printf("Modulus Division: %d\n", res);
            } else {
                printf("Error: Division by zero!\n");
            }
            break;
            
        default:
            printf("Invalid Option Selected\n");
			// default Case for Invalid attempts
    }

    return 0;
}