This problem is not very meaningful, the parent subclass of the definition of a variable with the same name is not standardized, but the interview is easy to ask in the written exam, to understand this problem can also help understanding inheritance.
Check the information, this is good, http://ayis.iteye.com/blog/221686 comment explanation is also very good.
To sum up here,
The parent class subclass variable refers to its own object: Direct access is a variable of its own definition.
The subclass Parent's own method is to access its own variables, which includes polymorphic situations, and the subclass method is accessed through the parent class variable.
My understanding is that the subclass object holds a copy of the parent object variable, that the variable of the same name is hidden, that the method in the parent class is shared and can only access variables in the parent class.