How to return a borrowed value from a function

Memory/Borrowing
2026-04-17T12:05:42+00:00
Return a borrowed value in Rust by using string slices (`&str`) for both the input parameter and the return type to avoid moving ownership.

You return a borrowed value by changing the function signature to accept a string slice (&str) and return a string slice (&str) instead of String types. This avoids moving ownership and allows the caller to keep using the original data.

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];
        }
    }
    &s[..]
}

fn main() {
    let my_string = String::from("hello world");
    let word = first_word(&my_string);
    println!("The first word is {}", word);
}