Boolean type support library

< c‎ | types
 
C
 
Type support
 

The C programming language, as of C99, supports Boolean arithmetic with the built-in type _Bool (see _Bool). When the header <stdbool.h> is included, the Boolean type is also accessible as bool.

Standard logical operators &&, ||, ! can be used with the Boolean type in any combination.

A program may undefine and perhaps then redefine the macros bool, true and false.

Macros

Macro name Expands to
bool _Bool
true integer constant 1
false integer constant 0
__bool_true_false_are_defined integer constant 1

Example

Run this code
#include <stdio.h>
#include <stdbool.h>
 
int main(void)
{
    bool a=true, b=false;
    printf("%d\n", a&&b);
    printf("%d\n", a||b);
    printf("%d\n", !b);
}

Output: 

0
1
1

See also