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Boolean values in C language

C - Using boolean values in C

Option – 1:

#include <stdbool.h>

The header stdbool.h in the C Standard Library for the C programming language contains four macros for a Boolean data type. The macros as defined in the ISO C standard are :

  • bool which expands to _Bool
  • true which expands to 1
  • false which expands to 0
  • __bool_true_false_are_defined which expands to 1
This header was introduced in C99.

Example: boolean values in C using stdbool.h

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

int main(void) {
    bool color = true;  // Could also be `bool color = 1;`
    while(color) {
        printf("This will run as long as color is true.\n");
        color = false;   
    }
    printf("color is false!\n");
    return 0;
}

Output:

This will run as long as color is true.
color is false!

Option – 2:

typedef enum { F, T } boolean;

Example: Using typedef enum { F, T } boolean;

#include <stdio.h>

typedef enum {
   F, T
}
boolean;


int main(void) {
	
	boolean color = T; 
    while(color) {
        printf("This will run as long as color is true.\n");
        color = F;   
    }
    printf("color is false!\n");
    return 0;
}

Output:

This will run as long as color is true.
color is false!


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