Scjp Chapter 2 Object Orientation

Front 1

Rules for overriding a method (6-7)
arg list
return type
access modifier
inheritance requirements
exceptions

Back 1

1. argument list must match exactly
2. return type must be same or subtype (co-variant)
3. access type can't be more restrictive (can be less restrictive)
4. subclass in same pkg can override public,protected,default
subclass in different pkg can
override public,protected
5. Can throw any more/broader checked exceptions, can throw any narrower, or unchecked exceptions

Front 2

Overloading method requirements/options
argument list
polymorphism limitation

Back 2

Method must have same name and
1. MUST change argument list
2. Overloaded method in subclass is NOT consider if method signature doesn't exist in parent class

Front 3

What does the term 'encapsulation' imply with respect to instance variables?

Back 3

Instance variables can't be accessed or updated directly, but can only be set through using getters and setters provided in the class where the instance variables are declared

Front 4

What Java principle is supported thru the use of the Java beans standard/convention?

Back 4

Encapsulation

Front 5

What must be true for the statement A "IS-A" B to be true?

Back 5

A must be a subclass of B, an interface implementation of B, or a subclass of an interface implementation of B.

Front 6

What must be true for the statement A "HAS-A" B to be true?

Back 6

Some code in class A must have a reference to an instance of class B

Q?: Does this mean that the reference to class B be must be an instance variable in class A? If a method in class A has a local variable reference to class B would A "HAS-A" B still be true? (I think not)