Ruby 检查偶数，浮点数 [英] Ruby check if even number, float

问题描述

我想检查数字是否为偶数！我尝试了以下方法:

I want to check if the number is even! I tried the following:

a = 4.0
a.is_a? Integer

=> false

a.even?

=> undefined method for Float

那么我如何检查数字是否为偶数?

So how can i check if the number is even?

推荐答案

如果您不确定您的变量是否在小数点后有任何内容，并且想在转换为整数之前检查以检查奇数/偶数，您可以这样做:

If you are unsure if your variable has anything after the decimal and would like to check before converting to integer to check odd/even, you could do something like this:

a = 4.6
b = 4.0

puts a%1==0 && a.to_i.even? #=> false
puts b%1==0 && a.to_i.even? #=> true

另外，如果你想创建一个偶数?Float 类的方法:

Additionally, if you want to create an even? method for the Float class:

class Float
  def even?
    self%1==0 && self.to_i.even?
  end
end

a = 4.6
b = 4.0

a.even? #=> false
b.even? #=> true

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