How to understand nil vs. empty vs. blank in Ruby

Question

I find myself repeatedly looking for a clear definition of the differences of nil?, blank?, and empty? in Ruby on Rails. Here\'s the

Answer 1

Don't forget any? which is generally !empty?. In Rails I typically check for the presence of something at the end of a statement with if something or unless something then use blank? where needed since it seems to work everywhere.

Answer 2

A special case is when trying to assess if a boolean value is nil:

false.present? == false
false.blank? == true
false.nil? == false

In this case the recommendation would be to use .nil?