Java Programing:

Inheritance is an example of what type of relationship?

a.	is-a	c.	was-a
b.	has-a	d.	had-a

2. Any new class you create from an existing class is called a(n) ____.

a.	base class	c.	derived class
b.	superclass	d.	extended class

3. Suppose there are three classes named Shape, Circle, and Square. What is the most likely relationship between them?

a.	Square is a superclass, and Shape and Circle are subclasses of Square.
b.	Shape is a superclass, and Circle and Square are subclasses of Shape.
c.	Shape, Circle, and Square are all sibling classes.
d.	These three classes cannot be related.

4. What is the correct syntax for defining a new class Parakeet based on the superclass Bird?

a.	class Parakeet isa Bird{ }
b.	class Bird defines Parakeet{ }
c.	class Bird hasa Parakeet{ }
d.	class Parakeet extends Bird{ }

What type of inheritance does Java support?

a.	single inheritance	c.	multiple inheritance
b.	double inheritance	d.	Java does not support inheritance.

7. If class Dog has a subclass Retriever, which of the following is true?

a.	Because of single inheritance, Dog can have no other subclasses.
b.	Because of single inheritance, Retriever can extend no other class except Dog.
c.	The relationship between these classes implies that Dog is-a Retriever.
d.	The relationship between these classes implies that Retriever has-a Dog.

8. Consider the following class definitions.

public class BClass {

private int x;

private double y;

public void print() { }

}

public class DClass extends BClass

{

private int a;

private int b;

public void print() { }

}

Suppose that you have the following statement.

DClass dObject = new DClass();

How many instance variables does dObject have?

a.	zero	c.	three
b.	two	d.	four

Consider the following class definitions.

public class BClass

{

private int x;

public void set(int a)

{

x = a;

}

public void print()

{

System.out.print(x);

}

}

public class DClass extends BClass

{

private int y;

public void set(int a, int b)

{

//Postcondition: x = a; y = b;

}

public void print(){ }

}

Which of the following correctly redefines the method print of DClass?

(i)

public void print()

{

System.out.print(x + " " + y);

}

(ii)

public void print()

{

super.print();

System.out.print(" " + y);

}

a. Only (i) b. Only (ii)

c. Both (i) and (ii) d. None of these