# <stdbool.h>

**[<stdbool.h>](https://en.cppreference.com/w/c/header/stdbool)** provides `bool`, `true`, and `false` (C99) as portable names for the `_Bool` type. Assigning any non-zero value to `bool` produces `1`, unlike `int` where `42` stays `42`.

In C23, `bool` became a built-in keyword, but including the header remains portable and harmless.

## Example

This example shows that bool truncates non-zero values to 1.

```c
// compile: gcc -std=c99 -o stdboolexample stdboolexample.c
// run: ./stdboolexample
// description: bool type behavior with various values

#include <stdbool.h>
#include <stdio.h>

int main() {
    bool a = 42;
    bool b = -1;
    bool c = 0;
    int d = 42;
    
    printf("bool(42) = %d\n", a);
    printf("bool(-1) = %d\n", b);
    printf("bool(0) = %d\n", c);
    printf("int(42) = %d\n", d);
    
    return 0;
}
```