fn main() {
    let s = String::from("hello world");
    let word = first_word(&s);

    // let hello = &s[0..5];
    // let world = &s[6..11];

    // s.clear();
    println!("word: {word} in {s}");
}

fn first_word(s: &str) -> &str {
    let bytes = s.as_bytes();

    for (i, &item) in bytes.iter().enumerate() {
        if item == b' ' {
            return &s[0..i];
        }
    }

    return &s[..];
}