JHTP自测题_第九章_面向对象编程-继承（Inheritance）

9.1Fill in the blanks in each of the following statements:

a)Inheritance is a form of software reusability in which new classes acquire the members of existing classes and embellish those classes with new capabilities.

b) A superclass’spublic and protectedmembers can be accessed in the superclass declarationand insubclass declarations.

c) In a(n)is-a or inheritancerelationship, an object of a subclass can also be treated as an object of its superclass.

d) In a(n)has-a or composition relationship, a class object has references to objects of other classes as members.

e) In single inheritance, a class exists in a(n)hierarchical relationship with its subclasses.

f) A superclass’spublic members are accessible anywhere that the program has a reference to an object of that superclass or to an object of one of its subclasses.

g) When an object of a subclass is instantiated, a superclassconstructor is called implicitly or explicitly.

h) Subclass constructors can call superclass constructors via thesuper keyword.

9.2State whether each of the following istrueorfalse. If a statement isfalse, explain why.

a) Superclass constructors are not inherited by subclasses. True

b) Ahas-arelationship is implemented via inheritance. False

c) ACarclass has anis-arelationship with theSteeringWheelandBrakesclasses. False

d) When a subclass redefines a superclass method by using the same signature, the subclass is said to overload that superclass method. False