In the spirit of keeping my code as concise as possible, in certain cases, I’ve started leaving off explicit “return” calls in my methods.

Earlier this week, however, I stumbled on a situation where it pays to be explicit.

I wanted to create a class instance method on a Person class that would return a particular person’s…particulars. That way my instance variables in a view could easily access someone’s details.

So, I went about my merry business on to what I thought would be a simple task.

Here’s the class (code that’s extraneous to the example has been omitted):

class Person
  include Mongoid::Document

  field :first_name,    type: String
  field :last_name,     type: String
  field :twitter_name,  type: String
  field :company,       type: String
  field :title,         type: String
  field :quote,         type: String

  def full_name
    "#{first_name} #{last_name}"
  end

end

OK, no big deal. I’ll just add a method called “details” to the class.

My logic was this: If a person has both a title and a company, return a string with those two bits of information. If a person is missing one of those bits, return a quote (if they have one). And finally, if they’ve got none of the above, just return an empty string.

Simple enough.

class Person
  include Mongoid::Document

  field :first_name,    type: String
  field :last_name,     type: String
  field :twitter_name,  type: String
  field :company,       type: String
  field :title,         type: String
  field :quote,         type: String

  def full_name
    "#{first_name} #{last_name}"
  end

  def details
    "#{title}, #{company}" unless title.blank? or company.blank?
    "#{quote}" unless quote.blank?
    ""
  end

end

To my surprise, “details” in its above implementation would return an empty string no matter what I tried. More specifically, it would return the last string in the method.

The following would return, as you might guess, “bar, yo!”

def details
  "foo"
  "#{title}, #{company}" unless title.blank? or company.blank?
  "#{quote}" unless quote.blank?
  "bar, yo!"
end

I eventually thought to try explicit return calls, and that’s when the method finally started working as expected.

def details
  return "#{title}, #{company}" unless title.blank? or company.blank?
  return "#{quote}" unless quote.blank?
  return ""

  # That last return is probably unnecessary, but after all 
  # of the preceding, I was going to give the method all the 
  # explicit returns it could handle. Plus, it's purdier.
end

So, long story short, continue being concise Ruby programmers. However, if you’re getting unexpected behavior, feel free to get explicit!