Check if two arrays have the same contents (in any order)

This doesn't require conversion to set:

a.sort == b.sort

for two arrays A and B:A and B have same contents if:(A-B).blank? and (B-A).blank?

or you can just check for:((A-B) + (B-A)).blank?

Also as suggested by @cort3z this solution als0 works for polymorphic arrays i.e

 A = [1 , "string", [1,2,3]] B = [[1,2,3] , "string", 1] (A-B).blank? and (B-A).blank? => true # while A.uniq.sort == B.uniq.sort will throw error `ArgumentError: comparison of Fixnum with String failed` 

::::::::::: EDIT :::::::::::::

As suggested in the comments, above solution fails for duplicates.Although as per the question that is not even required since the asker is not interested in duplicates(he is converting his arrays to set before checking and that masks duplicates and even if you look at the accepeted answer he is using a .uniq operator before checking and that too masks duplicates.). But still if duplicates interests you ,Just adding a check of count will fix the same(as per the question only one array can contain duplicates). So the final solution will be:A.size == B.size and ((A-B) + (B-A)).blank?

Ruby 2.6+

Ruby's introduced difference in 2.6.

This gives a very fast, very readable solution here, as follows:

a = [1, 2, 3, 4, 5, 6]b = [1, 2, 3, 4, 5, 6]a.difference(b).any?# => falsea.difference(b.reverse).any?# => falsea = [1, 2, 3, 4, 5, 6]b = [1, 2, 3]a.difference(b).any?# => true

Running the benchmarks:

a = Array.new(1000) { rand(100) }b = Array.new(1000) { rand(100) }Benchmark.ips do |x|  x.report('sort')   { a.sort == b.sort }    x.report('sort!')  { a.sort! == b.sort! }    x.report('to_set') { a.to_set == b.to_set }    x.report('minus')  { ((a - b) + (b - a)).empty? }    x.report('difference') { a.difference(b).any? }end      sort     13.908k (± 2.6%) i/s -     69.513k in   5.001443s     sort!     14.656k (± 3.0%) i/s -     73.736k in   5.035744s    to_set     5.125k  (± 2.9%) i/s -     26.023k in   5.082083s     minus     16.398k (± 2.2%) i/s -     83.181k in   5.074938sdifference     27.839k (± 5.2%) i/s -    141.048k in   5.080706s

Hope that helps someone!