# Boolean type

The `bool` type is a datatype which can be either `true` or `false`. The boolean type uses one byte of memory. It is used in comparisons and bitwise operations like `&`, `|`, and `!`.

    fn main() {
        let x = true;
        let y: bool = false; // with the boolean type annotation

        // Use of booleans in conditional expressions
        if x {
            println!("x is true");
        }
    }