To implement subclasses that inherit and override superclass methods Subclass objects automatically have the instance variables that are declared in the ...
Subclasses inherit from the superclass: ? All public methods that it does not override. ? All public instance variables. ? The Subclass can.
Java for instance
In other words every class
X is the subclass and Y is the superclass. 2. Which visibility modifier allows the data members of a superclass to be accessible to the instances of subclasses
instance of B. ? then B is a superclass of A a subclass graph need not be a tree a class may have multiple superclasses of#35# ece#627#winter#'13#.
Polymorphism and Subclasses. • A subclass instance is a superclass instance. – Polymorphism still works! – BankAccount ba = new CheckingAccount();.
Subclass inherits from superclass: all fields (state) and methods (behavior) Ability to replace any instance of a superclass with.
Methods that subclasses should implement are declared abstract. Instances of the subclasses are created but no instances of the superclass.
Superclass / Subclass. • Inheritance. • Overriding. • "isa" -- an instance of a subclass isa instance of the superclass. The subclass is just a refined form
Putting common code in a superclass then having subclasses inherit from it - they get all of its instance variables and methods
Only declare instance variables that are not part of the superclass objects A subclass inherits all methods that it does not override
The subclass inherits state and behavior in the form of variables and methods from its superclass The subclass can use just the items inherited from its
Subclasses inherit from the superclass: ? All public methods that it does not override ? All public instance variables ? The Subclass can
Therefore a subclass is a specialized version of a superclass It inherits all of the instance variables and methods defined by the superclass and add its
A subclass inherits the methods of its superclass The instance variables declared in the superclass are present in subclass objects balance =
The subclass exhibits the behaviors of its superclass and superclass constructor to initialize the instance variables inherited from the superclass
Enhance with new capabilities – Subclass extends superclass • Subclass – More specialized group of objects – Behaviors inherited from superclass
A subclass inherits all the methods and all the instance variables of the superclass and additionally it can have its own methods and instance variables 8 2
Subclass inherits from superclass: all fields (state) and methods (behavior) • You can use an object of the sub-class any place you expect a super-class