Compare two arrays in Ruby

Question

I'd like to know whether two Ruby arrays have the same elements, though not necessarily in the same order. Is there a native way to do this? The equality operators for Array seem to check whether the items are the same and the order is the same, and I need to relax the latter condition.

This would be extremely easy to write, I just wonder if there's a native idiom.

Answer 1

If you don't have duplicate items either, you could use Set instead of Array:

Set implements a collection of unordered values with no duplicates. This is a hybrid of Array's intuitive inter-operation facilities and Hash's fast lookup.

Example:

require 'set'
s1 = Set.new [1, 2, 3]   # -> #<Set: {1, 2, 3}>
s2 = [3, 2, 1].to_set    # -> #<Set: {3, 2, 1}>
s1 == s2                 # -> true