Ownership and Borrowing

Borrowing

Reading Without Owning

A reference (&) lets a function read a value without taking ownership, so the caller keeps using it afterward.

Program

Play the program to borrow message inside word_count and still print it.

borrowing.rs 
fn main() {
    let message = String::from("borrow me");
    let length = word_count(&message);
    println!("{message} has {length}");
}

fn word_count(text: &str) -> usize {
    text.split_whitespace().count()
}
reference `&message` borrows the value instead of moving it.
no ownership transfer `message` is still valid after the call.
split_whitespace `split_whitespace().count()` counts the words.