for loop - How to iterate a Vec<T> 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
    }
}

Answer 1

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);
    }
}

Playground