← Back to archive

Stdle #24 · closures · 2026-06-30

What does this Rust snippet output?

A past puzzle — fully playable. 4 attempts, hints on wrong guesses.

fn main() {
let v = vec![1, 2, 3];
let parts: Vec<String> =
v.iter().map(|x| format!("#{}", x)).collect();
println!("{}", parts.join(","));
}
Closures
4 attempts left

Answer & explanation