What is a better way to check for a nil object before calling a method on it?

Question

I have this method call I have to use...

financial_document.assets.length

But financial_document.assets could be nil.

I could use...

financial_document.assets.nil? ? '0' : financial_document.assets.length

Is there a less repetitive way to do that?

Answer 1

Dave W. Smith is on the right track.

Check this out: http://www.nach-vorne.de/2007/4/24/attr_accessor-on-steroids

One easy solution would look something like this:

class FinancialDocument
  attr_accessor :assets
  def assets
    @assets ||= Array.new
  end
  ...
end

Answer 2

Personally, I would use the or operator/keyword:

(financial_document.assets or []).length

Either way, .length is called on an array, giving you 0 if nil.