Why can't C have a boolean function?

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Hey, My Wi-Fi's been down and I haven't been on the computer lately. It's good to be back. So, you guys said a 'bool' function does not exist in C. However, upon a google search, I found it does. What exactly do you guys mean? Here's the code that you told me couldn't have a boolean function.

C

#include <stdio.h>
#include <stdbool.h> //I learned that you need to add stdbool.h to make the bool function work - Chris
 
int main(void) {
 printf("You will have life functions. You will get 3 lives.\n");
char life [3];
int aa;
printf("You have 3 lives");
printf("Press 'S' to start");
scanf("%i",&aa);
 
bool PlayerDied( PlayerData * pd )
{
   bool alive = false;
   --pd->Lives;       // player died - one less life
  return pd->Lives <= 0;
       alive = true;  // player still has a life left
   return alive;
}
 return 0;
}

What I have tried:

I read that boolean in C is used to store true and false variables.

Posted 26-Mar-21 4:36am

ModerateHacker;

Updated 26-Mar-21 23:35pm

KarstenK

v2

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Patrice T · Answer 1 · 2021-03-26T04:51:00

Solution 2

Quote:
Why can't C have a boolean function?

Traditionally in C, booleans are handled as ints.
True is any non 0 integer.
False is 0.

Posted 26-Mar-21 4:51am

Patrice T

Comments

ModerateHacker; 26-Mar-21 10:57am

Danke (German for thanks)

Greg Utas · Answer 2 · 2021-03-26T04:50:00

Solution 1

C didn't originally have bool, and maybe it still doesn't. It would simply be defined as some kind of int, possibly unsigned, with #define false 0 and #define true 1. Just like NULL isn't a keyword either, but rather some #define thing. This is now so standard that it looks like bool is part of the language.

Posted 26-Mar-21 4:50am

Greg Utas

Updated 26-Mar-21 4:51am

v2

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ModerateHacker; 26-Mar-21 10:57am

Makes sense. Thanks

OriginalGriff · Answer 3 · 2021-03-26T05:15:00

C still doesn't have bool/code> as a datatype - <code>_Bool was added at C99, but if you look at the stdbool.h header file, you will find that bool is a #define, as are true and false:

C++

/*===---- stdbool.h - Standard header for booleans -------------------------===
 *
 * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 * See https://llvm.org/LICENSE.txt for license information.
 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 *
 *===-----------------------------------------------------------------------===
 */

#ifndef __STDBOOL_H
#define __STDBOOL_H

/* Don't define bool, true, and false in C++, except as a GNU extension. */
#ifndef __cplusplus
#define bool _Bool
#define true 1
#define false 0
#elif defined(__GNUC__) && !defined(__STRICT_ANSI__)
/* Define _Bool as a GNU extension. */
#define _Bool bool
#if __cplusplus < 201103L
/* For C++98, define bool, false, true as a GNU extension. */
#define bool  bool
#define false false
#define true  true
#endif
#endif

#define __bool_true_false_are_defined 1

#endif /* __STDBOOL_H */

There is no "real bool" in C, and any nonzero value is always true as far as any condition text is concerned.

Rick York · Answer 4 · 2021-03-26T08:13:00

I see that old function is still alive and still in the wrong place as it was the last time you posted a question.

You still have not learned C does not support nested functions. This was pointed out in your last question. That function was pasted inside your main function and that is not allowed in C. You have to move it outside of the main function.

You also have to define a PlayerData structure for the function to be usable. The function accesses a Lives member of the structure so it should have that item in it along with any other data you want retain about the player. That is something YOU need to do.

Here's something might help : Data structures - C++ Tutorials[^]

Why can't C have a boolean function?

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