Lifetime Basic

Annotate references with lifetime parameters.

Difficulty

Advanced

Code

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

fn main() {
    let s1 = String::from("long string");
    let result;
    {
        let s2 = String::from("xyz");
        result = longest(s1.as_str(), s2.as_str());
        println!("longest: {}", result);
    }
}

Explanation

This example demonstrates how to use lifetime basic in Rust. Read the code carefully to understand the flow. Pay attention to where values are created, borrowed, moved, or consumed.

Key Concepts

• Rust's strong type system catches errors at compile time
• Ownership and borrowing rules ensure memory safety
• Pattern matching makes code expressive and exhaustive

Related Topics

Browse more examples in the lifetimes category to build a complete understanding of this topic.