rust / beginner
Snippet
Understanding Borrowing and References
Borrowing allows you to use values without taking ownership. By passing a reference `&`, the function borrows the value temporarily. The original owner `s1` remains valid after the function call. Rust enforces borrowing rules at compile time, preventing dangling references and data races.
snippet.rs
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fn main() {let s1 = String::from("Hello");let len = calculate_length(&s1);println!("The length of '{}' is {}.", s1, len);}fn calculate_length(s: &String) -> usize {s.len()}
Breakdown
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let s1 = String::from("Hello");
Creates a String value owned by `s1`.
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calculate_length(&s1)
Passes a reference to `s1`, not the value itself.
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fn calculate_length(s: &String)
Parameter `s` borrows a String reference. The function does not own the data.
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s.len()
Accesses the borrowed reference to get its length.