usage of attr_accessor in Rails

Question

When do you use attr_reader/attr_writer/attr_accessor in Rails models?

Answer 1

attr_accessor can be used for values you don't want to store in the database directly and that will only exist for the life of the object (e.g. passwords).

attr_reader can be used as one of several alternatives to doing something like this:

def instance_value
  "my value"
end