I find a great tutorial about the inject method which is written by Jay Field @ Jay Fields’ Thoughts – Ruby: inject. One of the example is converting an array into hash.
array_to_hash.rb

hash = [[:first_name, 'Shane'], [:last_name, 'Harvie']].inject({}) do |result, element|
  result[element.first] = element.last
  result
end

puts hash

Run the above ruby by ruby array_to_hash.ruby. Then you got

 

Done =)

Reference: Jay Fields’ Thoughts – Ruby: inject