Doing a request in Ruby

request.rb

require 'net/http'
require 'json'

uri = URI('https://restcountries.eu/rest/v2/name/united')
req = Net::HTTP::Get.new uri.path
res = Net::HTTP.start(uri.host, uri.port, use_ssl: uri.scheme == 'https') do |http|
  http.request(req)
end

countries = JSON.parse(res.body)
country_names = countries.map { |country| country['name'] }

puts country_names