ruby 红宝石 .ceil 和 .floor
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Ruby .ceil and .floor
提问by misokuan
I'm new to Ruby and I'm trying to figure out how ceiland floorworks as I get different answers when a fraction or a decimal number is used (similar value). Below is what I have tried:
我是新来的Ruby和我试图找出如何ceil和floor作品，我得到不同的答案时，分数或十进制数，使用（类似于值）。以下是我尝试过的：
puts 8/3.ceil == 2 #=> true
puts 8/3.floor == 2 #=> true
puts 2.67.ceil == 2 #=> false
puts 2.67.floor == 2 #=> true
From my understanding, ceilshould return a number higher and flooris a number lower. Hope someone can enlighten me on this. Thank you! :)
根据我的理解，ceil应该返回一个更高的数字并且floor是一个更低的数字。希望有人能在这方面启发我。谢谢！:)
回答by Andrey Deineko
Everything is returned correctly.
一切都正确返回。
puts 8/3.ceil == 2
#=> true, because 8/3 returns an Integer, 2
puts 8/3.floor == 2
#=> true, because 8/3 returns an Integer, 2
puts 2.67.ceil == 2
#=> false, because 2.67.ceil is 3
puts 2.67.floor == 2
#=> true, because 2.67.floor is 2
To make things of more sense here, you can convert results to Float:
为了使这里更有意义，您可以将结果转换为浮点数：
(8.to_f / 3).ceil == 2 #=> false
(8.to_f / 3).floor == 2 #=> true
2.67.ceil == 2 #=> false
2.67.floor == 2 #=> true
Another thing to bear in mind, that having written 8/3.ceilis actually 8 / (3.ceil), because the .binds stronger than /. (thx @tadman)
另一件要记住的事情，写了8/3.ceil实际上是8 / (3.ceil)，因为.绑定比/. （感谢@tadman）
Yet another thing to mention, is that (thx @Stefan):
还有一件事要提到的是（感谢@Stefan）：
There's also
fdivto perform floating point division, i.e.8.fdiv(3).ceil. And Ruby also comes with a niceRationalclass:(8/3r).ceil.
还有
fdiv执行浮点除法，即8.fdiv(3).ceil。Ruby 还提供了一个不错的Rational类：(8/3r).ceil.
