How to iterate a Vec with the indexed position?

Question

I need to iterate a Vec including the position for each iterated element. I'm sure this is already in the API but I cannot see it.

I need something like this:

fn main() {
    let v = vec![1; 10];
    for (pos, e) in v.iter() {
        // do something here
    }
}

score 170 · Accepted Answer · edited Nov 06 '19 at 19:14

170

You can use the Iterator::enumerate method:

fn main() {
    let v = vec![1; 10];
    for (pos, e) in v.iter().enumerate() {
        println!("Element at position {}: {:?}", pos, e);
    }
}

edited Nov 06 '19 at 19:14

Shepmaster

answered Mar 11 '15 at 15:44

@Shepmaster Is there also a way to do this and get the element directly instead of a reference to it? – Lukas Feb 28 '23 at 16:06
1

@Lukas [What is the difference between iter and into_iter?](https://stackoverflow.com/q/34733811/155423) – Shepmaster Apr 14 '23 at 21:04
if we call .next(), and then enumerate(), it don't keep track of the real index – wiiznokes3 Jun 16 '23 at 15:22

1 Answers1