Which of the following gems is used for authentication in Ruby on Rails? (check any that apply)

What does the expression x ||= y mean?

When rendering a partial in a view, how would you pass local variables for rendering?

Within a Rails controller, which code will prevent the parent controller's before_action :get_feature from running?

Which statement correctly describes a difference between the form helper methods form_tag and form_for?

What is before_action (formerly known as before_filter)?

which one is class method?

If you want to append an item to an array, what is the standard method?

Determine the value of the variable x after the execution of the following code. x = [1,2,3] x.pop until x.empty? x.push(4) while x.empty?

What file will rails look for given the following erb: <%= render 'some_partial' %>?

Imagine that you have two models: 'User' and 'Book', and a user can have only one book. How should the association look like in the 'User' model?