ruby - rails - Dealing with a Boolean False- It outputs nothing

问题

I have record in my db that is a boolean field (true/false).

The field is archived. When archived is true all these work great to output true:

  Rails.logger.info @commentable.archived
  Rails.logger.info @commentable.archived?
  Rails.logger.info !!@commentable.archived?

BUT when the archived is false, it outputs nothing for either of the above. How can I get an output of false when the field is FALSE?

Thanks

回答1:

Try .to_s on the field?

irb(main):001:0> false.to_s
=> "false"
irb(main):002:0> true.to_s
=> "true"
irb(main):003:0>

回答2:

I prefer to use .inspect for doing output to logging. I find its output more useful if you get a nil value.

ruby-1.8.7-p302 > nil.to_s
 => "" 
ruby-1.8.7-p302 > nil.inspect
 => "nil" 
ruby-1.8.7-p302 > false.to_s
 => "false" 
ruby-1.8.7-p302 > false.inspect
 => "false" 
ruby-1.8.7-p302 > 

回答3:

false.to_s == 'false', but Rails.logger.info seems to do the wrong thing here:

> puts true
true
> puts false
false
> Rails.logger.info true
true
> Rails.logger.info false

来源：https://stackoverflow.com/questions/4728130/ruby-rails-dealing-with-a-boolean-false-it-outputs-nothing