Question 1

Which statement is true when a superclass has protected instance variables?

Accepted Answer

A) A subclass object can assign an invalid value to the superclass's instance variables,thus leaving an object in an inconsistent state. 
B) Subclass methods are more likely to be written so that they depend on the superclass's data implementation. 
C) We may need to modify all the subclasses of the superclass if the superclass implementation changes. 
D) All of the above. 
A) A subclass object can assign an invalid value to the superclass's instance variables,thus leaving an object in an inconsistent state. 
B) Subclass methods are more likely to be written so that they depend on the superclass's data implementation. 
C) We may need to modify all the subclasses of the superclass if the superclass implementation changes. 
D) All of the above.

Question 2

Consider the classes below,declared in the same file:
Class A
{
Int a;
Public A()
{
A = 7;
}
}
Class B extends A
{
Int b;
Public B()
{
B = 8;
}
}
Which of the statements below is false?

Accepted Answer

A) Both variables a and b are instance variables. 
B) After the constructor for class B executes,the variable a will have the value 7. 
C) After the constructor for class B executes,the variable b will have the value 8. 
D) A reference of type A can be treated as a reference of type B. 
A) Both variables a and b are instance variables. 
B) After the constructor for class B executes,the variable a will have the value 7. 
C) After the constructor for class B executes,the variable b will have the value 8. 
D) A reference of type A can be treated as a reference of type B.

Which statement is true when a superclass has protected instance variables?

Consider the classes below,declared in the same file: Class A { Int a; Public A() { A = 7; } } Class B extends A { Int b; Public B() { B = 8; } } Which of the statements below is false?

Introduction to Computers and Java

Introduction to Java Applications

Introduction to Classes and Objects

Control Statements: Part 1

Control Statements: Part 2

Methods: a Deeper Look

Arrays and Arraylists

Classes and Objects: a Deeper Look

Object-Oriented Programming: Polymorphism

Exception Handling

Gui Components: Part 1

Graphics and Java 2D

Strings

Files,streams and Object Serialization

Generic Collections

Lambdas

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

Concurrency

Accessing Databases With Jdbc

JavaFX

Filters

Exam 9: Object Oriented Programming: Inheritance

Which statement is true when a superclass has protected instance variables?

Consider the classes below,declared in the same file: Class A { Int a; Public A() { A = 7; } } Class B extends A { Int b; Public B() { B = 8; } } Which of the statements below is false?

Introduction to Computers and Java

Introduction to Java Applications

Introduction to Classes and Objects

Control Statements: Part 1

Control Statements: Part 2

Methods: a Deeper Look

Arrays and Arraylists

Classes and Objects: a Deeper Look

Object-Oriented Programming: Polymorphism

Exception Handling

Gui Components: Part 1

Graphics and Java 2D

Strings

Files,streams and Object Serialization

Generic Collections

Lambdas

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

Concurrency

Accessing Databases With Jdbc

JavaFX

Filters