Exam 8: Inheritance

Consider an software system that will implement the following classes: Student, Professor, StaffMember, ContractWorker. List some common attributes of these classes. What would be a good abstract class from which these classes may be extended via inheritance?

When designing a class hierarchy, it is important that common features be ________________________ .

What does it mean for a class to be declared as final? What does it mean for a method to be declared as final?

Compare and contrast the private visibility modifier to the protected visibility modifier. Why is the protected visibility modifier a better choice in an inheritance hierarchy?

Which of the following methods are included in every class created in Java by inheritance?

Describe the behavior of the toString method and the equals method of the Object class.

Explain how a subclass can can access its parent classes private instance variables and methods.

The derived class created using inheritace is called ______________________ .

In order for derived classed to have access to encapsulated data members and methods of superclasses, the data members and methods should be declared using the ____________________ modifier.

A child class is allowed to define a method with the same name and parameter list as a method in the parent class.

It makes sense to declare most abstract methods as final.

Explain what it means for a child class to override a parent class. Why might this be useful?

Methods and variables declared as private in a parent class cannot be accessed in a child class.

The original class that is used to derive a new class using inheritance is called ____________________ .

Java supports multiple inheritance.

Explain the relevance of the Object class to the Java programming language.

Can a class be a parent of more than one subclass? Can a class be a child of more than one parent? Explain.

A programmer tries to create a subclass of String called MyString. When the programmer compiles her new class, the compiler produces the following message: MyString.java:1: cannot inherit from final java.lang.String public class MyString extends String { ^ 1 error Explain the cause of this error.

Once a method is overridden in a subclass, the original version can never be referenced from within the subclass.

What is an abstract class, and why might it be useful in an inheritance hierarchy?