What is the convention for methods which end with a question mark?
e.g. #all?, #kind_of?, directory?

Which is correctly handles the currency field? A) add_column :items, :price, :decimal, :precision => 8, :scale => 2 B) add_money :items, :price, currency: { present: false }

How can a partial called 'cart' be rendered from a controller called 'ProductsController', assuming the partial is in a directory called 'shared'?

What does the 4xx series of HTTP errors represent?

Which of the following validations in Rails checks for null fields?

Using ERB for views, what filename should be given to a partial called 'login'?

what does method ActiveSupport::Inflector.constantize do?

What is the difference between Post.find(3) and Post.find_by_id(3) ?

a = (1..3).reduce(-6){ |i,x| x + i } puts a

[1,2,3,5,8,13].include? '8'

The databases supported by ActiveRecord without any other gem are: