c calculator

here's a simple c calculator:

Code:

---

#include<stdio.h>
#include<conio.h>
#include<math.h>

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

        clrscr();

        printf("Enter two numbers and an operator in this form: \n");
        printf("<number1> <operator> <number2> (e.g. 7 + 4) \n");

        scanf("%lf %c %lf", &num1, &operator, &num2);

        if (operator == '+') {
        result = num1 + num2;
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        }
        else if (operator == '-' ) {
        result = num1 - num2;
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        }
        else if (operator == '*' ) {
        result = num1 * num2;
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        }
        else if (operator == '/' ) {
        result = num1 / num2;
        if (num1||num2 == 0) printf("Cannot divide with zero!");
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        } else
        printf("Invalid operator used.");

        return 0;
}

---

...but i have some problems with it.. can any1 please help me?

...i wanna use the switch() statement instead of using if's and else if's, but i don't know much about it...

...also, i want this program to run in an infinite loop (...while(1) or for(;;)...), until the user presses a hot-key.. like Ctrl-Q or Alt-X... but, sadly, i dnt also know how... srry..

..thanks in advance for your help... i'll appreciate them for sure... hehehe... -_+ :D

Quote:

---

...i wanna use the switch() statement instead of using if's and else if's, but i don't know much about it...

---

There is a C tutorial available on switch case.

Code:

---

#include<stdio.h>
#include<conio.h>
#include<math.h>

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

        clrscr();

        printf("Enter two numbers and an operator in this form: \n");
        printf("<number1> <operator> <number2> (e.g. 7 + 4) \n");

        while((scanf("%lf %c %lf", &num1, &operator, &num2)) != -1)
{
        switch(operator)
        {
    case '+':
    {
        result = num1 + num2;
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        break;
        }
        case '-':
    {
        result = num1 - num2;
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        break;
        }
        case '*':
    {
        result = num1 * num2;
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        break;
        }
        case  '/':
    {
        result = num1 / num2;
        if (num1 == 0||num2 == 0) printf("Cannot divide with zero!");
        printf("%g %c %g = %g\n", num1, operator, num2, result);
        break;
        }
    default:
    {
        printf("Invalid operator used.");
        break;
}
}
}
return 0;
}

---

control + z on windows or control + d on UNIX would stop the loop and end the program.

..ok,, thank you very much for the help..

i tried what you've said, and it worked.. thanks.. :D


..one more question about this program please.... ^.^

Code:

---

#include<stdio.h>
#include<conio.h>
#include<math.h>

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

        while(1)
        {
                clrscr();

                printf("SF7-CaLc by SeViLLa [aka:SF7]");
                printf("\n\nEnter two numbers and an operator in this form: \n");
                printf("<number1> <operator> <number2> (e.g. 7 + 4) \n");
                printf("\n\nEnter here: ");

                scanf("%lf %c %lf", &num1, &operator, &num2);

                switch(operator)
                {
                        case '+':
                        {
                        result = num1 + num2;
                        printf("\nOutput: %g %c %g = %g\n", num1, operator, num2, result);
                        getch();
                        break;
                        }

                        case '-':
                        {
                        result = num1 - num2;
                        printf("\nOutput: %g %c %g = %g\n", num1, operator, num2, result);
                        getch();
                        break;
                        }

                        case '*':
                        {
                        result = num1 * num2;
                        printf("\nOutput: %g %c %g = %g\n", num1, operator, num2, result);
                        getch();
                        break;
                        }

                        case  '/':
                        {
                        result = num1 / num2;
                        printf("\nOutput: %g %c %g = %g\n", num1, operator, num2, result);
                        getch();
                        break;
                        }

                        default:
                        {
                        printf("\nInvalid operator used.");
                        getch();
                        break;
                        }

                }
        }

        return 0;
}

---

...i want the program to exit using Alt+X ...is it possible for me to do that? if yes, please tell me how.... if you can post tutorials/help/tips regarding of the use of hot-keys in c, i would really appreciate it... thanks again... ^.^ :D