C Language Boolean Using the Intrinsic (built-in) Type _Bool
Example
C99
Added in the C standard version C99, _Bool is also a native C data type. It is capable of holding the values 0 (for false) and 1 (for true).
#include <stdio.h>
int main(void) {
_Bool x = 1;
_Bool y = 0;
if(x) /* Equivalent to if (x == 1) */
{
puts("This will print!");
}
if (!y) /* Equivalent to if (y == 0) */
{
puts("This will also print!");
}
}
_Bool is an integer type but has special rules for conversions from other types. The result is analogous to the usage of other types in if expressions. In the following
_Bool z = X;
- If
Xhas an arithmetic type (is any kind of number),zbecomes0ifX == 0. Otherwisezbecomes1. - If
Xhas a pointer type,zbecomes0ifXis a null pointer and1otherwise.
To use nicer spellings bool, false and true you need to use <stdbool.h>.
