如何保存红宝石中的浮点数 [英] How do I preserve my float number in ruby

问题描述

因此，我正在尝试一些代码以将数字转换为字符串.但是，我注意到在某些情况下它不会保留最后两位小数.例如，我键入1.01和1.04作为加法，然后得到2.04.如果我只输入1.05，它将保留该数字并准确返回.我知道发生了什么事.我不知道如何防止它被四舍五入.我是否应该只考虑将(1.01 + 1.04)发送给self作为一个输入?

So I'm trying some code out to convert numbers into strings. However, I noticed that in certain cases it does not preserve the last two decimal places. For instance I type 1.01 and 1.04 for addition and I get back 2.04. If I type just 1.05 it preserves the number and returns it exactly. I get whats going on things are being rounded. I don't know how to prevent it from being rounded though. Should I just consider sending (1.01+1.04) to self as only one input?

警告！我还没有尝试过，所以不知道它是否受支持:

Warning! I haven't tried this yet so don't know if its supported:

 user_input = (1.04+1.01) #entry from user
 user_input = gets.to_f
 user_input.to_test_string

到目前为止我所拥有的:

What I have so far:

    class Float
     def to_test_string

      cents = self % 1
      dollars = self - cents
      cents = cents * 100

      text = "#{dollars.to_i.en.numwords} dollars and #{cents.to_i.en.numwords} cents"

      puts text
      text
     end
    end
  puts "Enter two great floating point numbers for adding"
  puts "First number"
  c = gets.to_f
  puts "Second number"
  d = gets.to_f
  e = c+d
  puts e.to_test_string
  puts "Enter a great floating number! Example 10.34"
  a = gets.to_f 
  puts a.to_test_string

感谢您的帮助！张贴一些代码，以便我可以尝试！

Thanks for the help! Post some code up so I can try!

推荐答案

首先:永远不要用浮点数赚钱—

First of all: never use float for money — Use Float or Decimal for Accounting Application Dollar Amount?

irb> x = 1.01 + 1.04
=> 2.05
irb> y = x % 1
=> 0.04999999999999982
irb> (y * 100).to_i
=> 4

但是非常想要的话:

irb> (y * 100).round.to_i
=> 5

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