Sort Ruby Hash by order in array of keys

Question

I have a hash:

sample = { bar: 200, foo: 100, baz: 100 }

How do I sort sample using the order of keys in sort_order:

sort_order = [:foo, :bar, :baz, :qux, :quux]

Expected result:

sample #=> { foo: 100, bar: 200, baz: 100 }

All I can come up with is

new_hash = {}
sort_order.each{|k| new_hash[k] = sample[k] unless sample[k].nil? }
sample = new_hash

There's got to be a better way. Hints?

Keys without values should not be present, i.e. number of keys remain the same, which isn't the case with Sort Hash Keys based on order of same keys in array

Answer 1

A functional approach using the intersection of keys:

new_sample = (sort_order & sample.keys).map { |k| [k, sample[k]] }.to_h
#=> {:foo=>100, :bar=>200, :baz=>100}

As @Stefan noted, the abstraction Hash#slice from ActiveSupport's pretty much does the job:

require 'active_support/core_ext/hash'
new_sample = sample.slice(*sort_order)
#=> {:foo=>100, :bar=>200, :baz=>100}

Answer 2

Please, see my this answer:

sort_order = [:foo, :bar, :baz, :qux, :quux, :corge, :grault,
              :garply, :waldo, :fred, :plugh, :xyzzy, :thud]
sample = { bar: 200, foo: 100, baz: 100 }

sample.sort_by {|k, _| sort_order.index(k)}.to_h
=> {:foo=>100, :bar=>200, :baz=>100}