Gaining karma by learning about_nil.rb

* In most other languages, nil or NULL is an
  undefined thing, in Ruby, it's actually an
  object

[#54146135]
Gaining karma by learning about_nil.rb

* If an undefined method is called on nil, it will
  raise a NoMethodError with a message stating
  that that method is not found

* This is the most common error in Rails.

[#54146135]
Gaining karma by learning about_nil.rb

* The nil object has some methods defined on it.

[#54146135]
Merge pull request #1 from annkarpinski/54146135_about_nil_master

about nil master\

[Delivers #54146135]