如何根据每天打印月份的日子（例如：苏莫图我们……等）？
我有一个数字1-31的大字符串。 我怎么能把这个月的名字集中在一起？
我的代码：
class Month attr_reader :month, :year def initialize( month, year) @month = month @year = year end def month_names names_of_months = {1 => 'January', 2 => 'February', 3 => 'March', 4 => 'April', 5 => 'May', 6 => 'June', 7 => 'July', 8 => 'August', 9 => 'September', 10 => 'October', 11 => 'November', 12 => 'December'} return names_of_months[@month] end def length days_of_months = {1 => 31, 2 => 28, 3 => 31, 4 => 30, 5 => 31, 6 => 30, 7 => 31, 8 => 31, 9 => 30, 10 => 31, 11 => 30, 12 => 31} return days_of_months[@month] end def to_s output = "#{month_names} #{year}\nSu Mo Tu We Th Fr Sa\n" (1..length).each do |day| output << day.to_s end output end end 终端状态：
Failure: TestMonth#test_to_s_on_jan_2017 [test/test_month.rb:39] Minitest::Assertion: --- expected +++ actual @@ -1,9 +1,3 @@ -"January 2017 +"January 2017 Su Mo Tu We Th Fr Sa - 1 2 3 4 5 6 7 - 8 9 10 11 12 13 14 -15 16 17 18 19 20 21 -22 23 24 25 26 27 28 -29 30 31 - -" +12345678910111213141516171819202122232425262728293031"
Ruby中的String类有一个center方法：
weekdays = "Su Mo Tu We Th Fr Sa" month = "#{month_names} #{year}" output = [ month.center(weekdays.size), weekdays ].join("\n") puts output # April 2015 # Su Mo Tu We Th Fr Sa
以下内容并未真正回答您的问题。 它只是对代码的完全重写，因为我很无聊：
require 'date' class Month attr_reader :month, :year def initialize(month, year) @month = month @year = year end def first_of_month Date.new(year, month, 1) end def last_of_month Date.new(year, month, -1) end def month_name last_of_month.strftime('%B') end def days_in_month last_of_month.day end def to_s [].tap do |out| out << header out << weekdays grouped_days.each do |days| out << days.map { |day| day.to_s.rjust(2) }.join(' ') end end.join("\n") end private def header "#{month_name} #{year}".center(weekdays.size) end def weekdays 'Su Mo Tu We Th Fr Sa' end def grouped_days days = (1..days_in_month).to_a first_of_month.wday.times { days.unshift(nil) } days.each_slice(7) end end Month.new(4, 2015).to_s # April 2015 # Su Mo Tu We Th Fr Sa # 1 2 3 4 # 5 6 7 8 9 10 11 # 12 13 14 15 16 17 18 # 19 20 21 22 23 24 25 # 26 27 28 29 30