calculator.c

# include <stdio.h>

int main() {

    char op;
    double n1,n2;

    printf("Enter an operator (+, -, *,): ");
    scanf("%c", &op);

    printf("Enter two operands: ");
    scanf("%lf %lf",&n1, &n2);

    switch(op)
    {
        case '+':
            printf("%.1lf + %.1lf = %.1lf\n",n1, n2, n1 + n2);
            break;

        case '-':
            printf("%.1lf - %.1lf = %.1lf\n",n1, n2, n1 - n2);
            break;

        case '*':
            printf("%.1lf * %.1lf = %.1lf\n",n1, n2, n1 * n2);
            break;

        case '/':
            printf("%.1lf / %.1lf = %.1lf\n",n1, n2, n1 / n2);
            break;

        // operator doesn't match any case constant (+, -, *, /)
        default:
            printf("Error! operator is not correct");
    }
    
    return 0;
}