Boolean returns in C

Hi hi, I'm writing a program that tests data we input then decides whether to proceed or stop with the program. This is a programming assignment that I've been working on for about a week, but I'm stuck on something :'(.

Basically, I have three functions that must proceed and check out as true before any calculations are done.

Code:

---

bool getBounds(int lowB, int uppB)
{
  if (lowB >=-25)
      if (lowB <=-1)
        printf("\nLB works");
          // This is where I want it to be known as TRUE

      else
        printf("\nLB doesnt work");
          // This is where it is false

  else
      printf("\nLB doesnt work");
          // This is where it is false

  if (uppB >=1)
      if (lowB <=25)
        printf("\nUB works");
          // TRUE\
 
      else
        printf("\nUB doesnt work");
            // This is where it is false
       
  else
      printf("\nLB doesnt work");
            // This is where it is false

}

---

Is what I have so far, I've tried returning 1 as True and 0 as False, but I recieve a syntax error when trying to compile. I cannot use exit() or abort().

Does anyone have any possible tips that might point me in the right direction?

Can I just return either a 1 or a 0?

Thank you for any tips you can provide.

I read through the two stickies (including the homework) and I do not believe I am violating anything. If I am I will be more than happy to rewrite it.

Use lot's more braces to make your intentions obvious.
Like

Code:

---

  if (lowB >=-25) {
      if (lowB <=-1) {
        printf("\nLB works");
      }
  }

---

Also, your function needs a return statement if it's to return a value

> Can I just return either a 1 or a 0?
Yes.

Prior to C99, there was no boolean type in C. You can get around it various ways. If you're using C99, you can include <stdbool.h> and use _Bool, or its macro bool. If you don't have a C99 compiler...

Code:

---

typedef enum { false, true } bool;
/* perhaps... */
#define bool int
#define false 0
#define true 1
/* or maybe... */
typedef int bool;
/* etc... */

---

Quzah.

Thanks much, I'm going to give it another go soon. Cheers

Is something like this the desired end result?

Code:

---

bool getBounds(int lowB, int uppB)
{
  return lowB >= -25 && lowB <= -1 && uppB >=1 && lowB <= 25;
}

---

Quote:

---

Originally Posted by quzah

Prior to C99, there was no boolean type in C. You can get around it various ways. If you're using C99, you can include <stdbool.h> and use _Bool, or its macro bool. If you don't have a C99 compiler...

Code:

---

typedef enum { false, true } bool;
/* perhaps... */
#define bool int
#define false 0
#define true 1
/* or maybe... */
typedef int bool;
/* etc... */

---

Quzah.

---

And if you'd like to know why none of these options are perfect solutions (hence the real need to add bool to the language) read this

We use the enum method where I work and indeed the following code will not pass code reviewing.

Code:

---

BOOL b = ( i == j );

---

What we have to do is

Code:

---

BOOL b = ( i == j ) ? TRUE : FALSE;

---

or with a helper macro

Code:

---

BOOL b = BOOL_VAL( i == j );

---

Those solutions are rather annoying :)

Quote:

---

Originally Posted by iMalc

And if you'd like to know why none of these options are perfect solutions (hence the real need to add bool to the language) read this

---

There is a real bool. It's called _Bool, and was added in C99. You know, just like I mentioned in the first sentence of the text you quoted.


Quzah.

I'm still having a little trouble figuring out what I'm supposed to do once I actually return either a true false statement. A false statement is supposed to let the program quit through main, while a true statement continues with all the checkpoints before donig calculations.

I'll be at work on it, thanks for the help so far, I'm slowly being able to figure it out :)

You should be able to do what you've described with an if statement:

Code:

---

if(!function()) return 1;

---

Quote:

---

Originally Posted by Laserve

We use the enum method where I work and indeed the following code will not pass code reviewing.

Code:

---

BOOL b = ( i == j );

---

What we have to do is

Code:

---

BOOL b = ( i == j ) ? TRUE : FALSE;

---

or with a helper macro

Code:

---

BOOL b = BOOL_VAL( i == j );

---

Those solutions are rather annoying :)

---

Aye. I prefer plain 1 or 0, as opposed to silly macros.

Thanks for the help y'all. I have this portion figured out now and working on another. Y'all have been a great help!