Thread: Making a calculator run again!

Put everything you want to be repeated inside a while (1) loop (in this case, everything after your variable definitions).

You'll also need the code in red, below, to be added as indicated:

Code:

   else
       {
       printf ("INVALID CHOICE! EXITTING!\n");
       return 0;
       }
   }   /* now marks the end of the new while(1) loop */
}   /* new end of main() */

"Exiting" only has one 'T' in it.

How's the program run?

It makes no sense to me to put the WHOLE code in a while loop!

That would be :

Code:

preprocessors
int main ()
{
while(1)
{
the code
}
}

something like this, or what!?????



And I have another idea but, I do not know if it is right and dop not know how to do it correctly


asign choices a function for each, then put those all functions into a big function and run it till the user decides to quit it!


Pls correct me if I am wrong

I did it with the while loop, but I do not understand why u have to put the argument 1 in the
while (1)! It annoys me because I do not understand it lol!


Another thing I am trying to make is make a char type variable and make that char, when pressed, exit the program but I do not know how to make that, can you help??? Thanks

Originally Posted by cookie

I did it with the while loop, but I do not understand why u have to put the argument 1 in the
while (1)! It annoys me because I do not understand it lol!


Another thing I am trying to make is make a char type variable and make that char, when pressed, exit the program but I do not know how to make that, can you help??? Thanks

OK, we're looking at the while() loop:

Code:

while(1)

print up a header for the page  (Welcome to MyProgram, etc.)
print up a list of the menu choices:
#1. Play my little guessing game
#2. Read my blog entry for yesterday
#3. Look at pics of my dog when it got too close to a porcupine (ouch!)
#4. Quit the Program.
etc.

print query for user's choice:
"Please choose a number and press Enter"

scanf("%d", &number); 

switch number
   case 1: guessingGame();
   case 2: ReadBlog();
   case 3: DogPics();
   case 4: return() or exit();
etc.

So the menu will always be returned to after the user finishes one area. He can choose another choice, or he can choose to quit.

First of all, thanks for the while loops explanation! I get it now!
What I meant with the unclear part is that I want to make a button that will exit the program!

I thought I was supposed to make a char type variable! If I am right with the char type variable, how do I make a function that will exit the program when I type in that char?


I hope I make myself clear now

I know what a while loop is, but how does while(1) work? Since 1 is a constant would loop forever until a break is called, or is there something I am missing here...

Since the option to quit is either going to be a yes or a no you could have a bool called something like 'quit' then loop the program until quit is not 0. Heres an example, its pretty crude, but anyway:

Code:

#include <stdio.h>

bool Continue()
{
    char ans='x';
    while(ans!='y' && ans!='n')//Loop until a y or n is entered
    {
        printf("Run this program again? y/n: ");
        ans=getchar(); //get answer
        getchar();               
    }   
    if(ans=='y') return 0; 
    else         return 1; //if answer is no then set quit to 1
}

int main()
{
    bool quit = 0;
    while(quit == 0) //The program runs until quit is not 0
    {
        printf("Do Stuff\nDo Stuff\nDo Stuff\n");
        quit = Continue(); //Call this function to get a value for quit
    }           
}

In C there is no built-in bool type. In C99 there is a standard header file <stdbool.h> which #define's true and false as 1 and 0, resp. Only in C++ is bool a built-in type.

Oh, I did not know that. I use Dev-C++ and it works for me. Still you could just replace it with an int, short, or char and it would work fine.

Check that you're not inadvertently compiling your C in C++ mode.

Originally Posted by mike_g

Oh, I did not know that. I use Dev-C++ and it works for me. Still you could just replace it with an int, short, or char and it would work fine.

The stdbool.h was just an alternative for your int. If you still want to use th bool which u have already done. Then include this header.

Or you will have to replace all booll by int. And dont replace it with char. Becuase getchar return int not a char.

ssharish2005