ruby-on-rails - 获取两个日期之间的月份和年份的唯一数组

Question

我有两个 Date 对象，例如:

first = Fri, 02 Dec 2016 
last = Wed, 01 Mar 2017

获取月份和年份之间唯一的数组的最有效方法是什么？在这种情况下，我追求的是:

Dec 2016
Jan 2017
Feb 2017
Mar 2017

Answer 1

require 'date'

def doit(first, last)
  first = first << 1
  (12*last.year + last.month - 12*first.year - first.month + 1).
    times.map { |i| (first = first >> 1).strftime("%b %Y") }
end

first = Date.parse('Fri, 02 Dec 2016')
last  = Date.parse('Wed, 01 Mar 2017')

doit(first, last)
  #=> ["Dec 2016", "Jan 2017", "Feb 2017", "Mar 2017"]

注意

(12*last.year + last.month - 12*first.year - first.month + 1)

等于范围内的月数。