I have this situation:
class Employee < ActiveRecord::Base belongs_to :designation end
class Designation < ActiveRecord::Base end
I do the following at the irb console:
Step 1: Find an employee
emp = Employee.find 3
=> #<Employee:0x35a7d34 @attributes={"designation_id"=>"3", "id"=>"3", "division_id"=>"4"}>
Step 2: Save the designation in a variable des
des = emp.designation
=> #<Designation:0x35a49b8 @attributes={"name"=>"Project Manager", "id"=>"3", "division_id"=>nil}>
des
=> #<Designation:0x35a49b8 @attributes={"name"=>"Project Manager", "id"=>"3", "division_id"=>nil}>
Step 3: Replace the employee's designation
emp.designation = Designation.find 1
=> #<Designation:0x359fa80 @attributes={"name"=>"Trainee", "id"=>"1", "division_id"=>nil}>
Step 4: Notice that the variable des's object id has changed
des
=> #<Designation:0x359fa80 @attributes={"name"=>"Trainee", "id"=>"1", "division_id"=>nil}>
At step 4 i would NOT EXPECT the reference of des to change as des at step 2 had reference to object Designation:0x35a49b8
However if i change emp.designation the variable des automagically changes to refer to the same object that emp.designation is referring to! It's almost like whenever I refer to des, emp.designation seems to be re-evaluated all over again!
