age difference

age_difference.rb

require 'pry-byebug'
require 'active_support/all'

dates = {
  "a" => "10.01.2000",
  "b" => "15.02.2000",
}

def seconds_to_units(seconds)
  '%d days, %d hours, %d minutes, %d seconds' %
    # the .reverse lets us put the larger units first for readability
    [24,60,60].reverse.inject([seconds]) {|result, unitsize|
      result[0,0] = result.shift.divmod(unitsize)
      result
    }
end

dates.to_a.combination(2).to_a.each do |(left_nick, left_date), (right_nick, right_date)|
  left_date = Time.parse(left_date).to_i
  right_date = Time.parse(right_date).to_i
  difference = (left_date - right_date).abs
  text_difference = seconds_to_units(difference)
  puts "Разница между #{left_nick} и #{right_nick} составляет #{text_difference}"
end

Gemfile

# frozen_string_literal: true

source "https://rubygems.org"

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

# gem "rails"

gem 'rails', '~> 5.0'
gem 'pry-byebug'