#5 inheritance (2.1 +2.2)

Question 1

override

Answer 1

a subclass can override (redefine) methods in the superclass
same name and signature

(uses super() to call the original method)

Question 2

dynamic dispatch/late binding/dynamic method binding

Answer 2

overriding, happens during program execution

Question 3

nonstatic: how is overriding determined

Answer 3

the type of object (not the reference) determines which method will be called

Question 4

static: how is overriding determined

Answer 4

the type of the variable determines which method will be called

Question 5

overriding and privacy

Answer 5

subclasses can make overridden methods more private. they cannot make them more public.

Question 6

private things in a superclass

Answer 6

subclass cannot directly access private fields and methods in its superclass(es)
CAN THET BE OVERRIDEN? no

Question 7

protected

Answer 7

subclasses have access (same package or not)

Question 8

subclasses and super classes can have fields with the same name how

Answer 8

you use super. to differentiate between the two. subclass takes precedence. super. only refers to the immediate super class

Question 9

final with overriding

Answer 9

final methods cannot be overridden (nor can private, b/c they are implicitly final)

Question 10

final with inheritance

Answer 10

final:
cannot be extended (have subclasses)
it’s methods are implicitly final
(string is a java library final class)

Question 11

what can a super class access?

Answer 11

only fields and methods in its class (doesn’t know subclass exists)

Question 12

upcasting

Answer 12

cast a subclass reference to a superclass reference

Question 13

downcasting

Answer 13

cast a superclass reference to a subclass reference

Question 14

cast a car to a vehicle

Answer 14

ALWAYS VALID

Question 15

cast a vehicle to a car

Answer 15

ONLY IF VEHICLE IS ACTUALLY OF TYPE CAR!