Boolean values in C language

Last update on December 20 2024 13:15:20 (UTC/GMT +8 hours)

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

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!