Question

I have an array with different IDs going from 1 to 4000. I need to add some elements in a database with an ID that would go in that array. Since the biggest ID possible is 4000 (which is not that much in my case), I’d like to be able to find the lowest unused ID possible I could use for my new element.

I would know how to do that in C++, but since I’m pretty new in Ruby, I’m asking for help. in C++, I would write a loop in which I would check if array[i] == array[i+1] – 1. If not the case, then the new id would be array[i] + 1.

I have just no idea how to write that in Ruby.

Answer 1

array = [1, 2, 3, 5, 6]
(1..4000).to_a.-(array).min