Boolean type support library

 

C

Language

headers

Type support

Dynamic memory management

Error handling

Program utilities

Variadic function support

Date and time utilities

Strings library

Algorithms

Numerics

Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

Technical Specifications

 

Type support

size_t

ptrdiff_t

NULL

max_align_t (since C11)

offsetof

Numeric limits

 

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);
}

Possible output:

0
1
1

See also

C++ documentation for bool