ruby - 红宝石日期减法

Question

我对 Ruby 中的日期减法有疑问

"2011-03-29".to_date - "2011-03-20".to_date #=> (9/1)
("2011-03-29".to_date - "2011-03-20".to_date).to_i #=> 9

似乎它以天数返回日期之间的差异。

现在我的问题是返回日期差异的年数、月数、天数

ie ("2011-03-29".to_date - "2011-03-20".to_date)

应该返回

0 years, 0 month and 9 days

谢谢。

Answer 1

你可以试试这个链接：

http://api.rubyonrails.org/classes/ActionView/Helpers/DateHelper.html#method-i-distance_of_time_in_words

或者

  def time_diff_in_natural_language(from_time, to_time)
    from_time = from_time.to_time if from_time.respond_to?(:to_time)
    to_time = to_time.to_time if to_time.respond_to?(:to_time)
    distance_in_seconds = ((to_time - from_time).abs).round
    components = []

    %w(year month week day).each do |interval|
      # For each interval type, if the amount of time remaining is greater than
      # one unit, calculate how many units fit into the remaining time.
      if distance_in_seconds >= 1.send(interval)
        delta = (distance_in_seconds / 1.send(interval)).floor
        distance_in_seconds -= delta.send(interval)
        components << pluralize(delta, interval)
      end
    end

    components.join(", ")
  end

  time_diff_in_natural_language(Time.now, 2.5.years.ago)
  >> 2 years, 6 months, 2 days

参考：在Rails中，用英文显示两个日期之间的时间

Answer 2

我知道这有点脏，但你有没有试过：

result = Date.new(0) + ("2011-03-29".to_date - "2011-03-20".to_date)
puts "#{result.year} years, #{result.month - 1} months and #{result.day} days"