Advanced Rust Development Tutorials, Guides & Insights

Lifetimes in Rust prevent dangling references by ensuring that references are always valid. The compiler checks lifetimes to guarantee that no references outlive the data they point to.

fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
    if x.len() > y.len() {
        x
    } else {
        y
    }
}

fn main() {
    let string1 = String::from("long string is long");
    let result;
    {
        let string2 = String::from("xyz");
        result = longest(string1.as_str(), string2.as_str());
    }
    // println!("The longest string is {}", result); // Error: string2 no longer exists
}