What is the fastest way to sort a Hash?

Question

People often ask what is the best way to sort a hash, but then they don\'t ask the needed follow-up question about what is the fastest way, which really determ

Answer 1

This is a comparison of sort and sort_by when accessing a more complex object:

require 'fruity'

RUBY_VERSION # => "2.2.2"

class Foo
  attr_reader :key
  def initialize(k)
    @key = k
  end

  def <=>(b)
    self.key <=> b.key
  end
end

HASH = Hash[[*(1..100)].shuffle.map{ |k| [Foo.new(k), 1] }]
compare do
  _sort1 { HASH.sort.to_h }
  _sort_by { HASH.sort_by{ |k,v| k.key }.to_h }
end
# >> Running each test 32 times. Test will take about 1 second.
# >> _sort_by is faster than _sort1 by 2.7x ± 0.1