Ruby，检查日期是否是周末？
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Ruby, check if date is a weekend?
提问by General_9
I have a DailyQuote model in my rails application which has a dateand pricefor a stock. Data in the database has been captured for this model including weekends. The weekend price values have been set as 0.
我的 rails 应用程序中有一个 DailyQuote 模型，它有股票的日期和价格。数据库中的数据已为此模型捕获，包括周末。周末价格值已设置为 0。
I want to change all the weekend prices for Saturday and Sunday to whatever the price was on Friday. What is the best way to do this in Ruby? To identify if a date falls on a Sat or Sun and change its value to the Fri of that weekend?
我想将周六和周日的所有周末价格更改为周五的价格。在 Ruby 中执行此操作的最佳方法是什么？确定日期是星期六还是星期日并将其值更改为那个周末的星期五？
采纳答案by robustus
require 'date'
today = Date.today
ask_price_for = (today.wday == 6) ? today - 1 : (today.wday == 0) ? today - 2 : today
or
或者
require 'date'
today = Date.today
ask_price_for = (today.saturday?) ? today - 1 : (today.sunday?) ? today - 2 : today
ask_price_fornow holds a date for which you would want to ask the price for.
ask_price_for现在有一个您想要询问价格的日期。
Getting the actual price which is corresponding to you date depends on your Model and your ORM-Library (i.e. ActiveRecord).
获取与您的日期相对应的实际价格取决于您的模型和您的 ORM 库（即 ActiveRecord）。
回答by tsundoku
回答by heading_to_tahiti
The simplest approach:
最简单的方法：
today = Date.today
if today.saturday? || today.sunday?
puts "Today is a weekend!"
end
You can also do this for any other day of the week. Ruby is fantastic and offers a lot of cool methods like this. I suggest when you get stumped take a look at what's available to the class by running .methodson it. So if you run Date.today.methodsyou will see these available.
您也可以在一周中的任何一天执行此操作。Ruby 非常棒，并提供了很多像这样很酷的方法。我建议当你遇到困难时，通过运行来看看类可以.methods使用什么。因此，如果您运行，Date.today.methods您将看到这些可用。
回答by peter
class Time
def is_weekend?
[0, 6, 7].include?(wday)
end
end
time = Time.new
puts "Current Time : " + time.inspect
puts time.is_weekend?
回答by cafe_
Date.today.instance_eval { saturday? || sunday? }
Date.today.instance_eval { 星期六？|| 星期日？}
