Boolean type support library

 

C

Compiler support

Language

Headers

Type support

Program utilities

Variadic function support

Error handling

Dynamic memory management

Strings library

Algorithms

Numerics

Date and time utilities

Input/output support

Localization support

Concurrency support (C11)

Technical Specifications

Symbol index

 

Type support

size_t

ptrdiff_t

nullptr_t (C23)

NULL

max_align_t (C11)

offsetof

Numeric limits

Fixed width integer types (C99)

 

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

C++ documentation for bool