Name the option. Question 1 Classes that are derived from an existing class thro

Question

Name the option.

Question 1

Classes that are derived from an existing class through inheritance have a "has-a" relationship.

Question 1 options:

Question 2

A class can only be used as a superclass once.

Question 2 options:

Question 3

A subclass can extend only one superclass.

Question 3 options:

Question 4

A subclass can refer to...

Question 4 options:

the private instance variables of the superclass

the private instance methods of the superclass

the public instance methods of the superclass

none of the above

Question 5

What can an abstract class contain?

Question 5 options:

constructors, instance variables, instance methods, abstract methods, static methods, static variables

constructors, instance variables, instance methods, abstract methods,

abstract methods, static methods, static variables

instance variables, instance methods, abstract method

Question 6

What is the use of the keyword super in a subclass?

Question 6 options:

It provides access to the constructor of the superclass.

It provides access to an instance method of the superclass.

It provides access to a public instance variable of the superclass.

All of the above.

None of the above

Question 7

What is the purpose of a constructor in a subclass.

Question 7 options:

To initialize value of the subclasses' private and public instance variable through assignment statements (eg. this.x = 1)

To initialize the value of the subclasses' public and private instance variables and the superclasses' private and public instance variables through assignment statements. (super.x = 1; this.y = 2)

To use a super constructor to initialize the value of the superclasses' instance variables.

To initialize value of the subclasses' private and public instance variable through assignment statements (eg. this.x = 1) and
use a super constructor to initialize the value of the superclasses' instance variables.

Question 8

Abstract classes can not be instantiated.

Question 8 options:

Question 9

Which of the following is a correct implementation of polymorphism. Note, object B extends object A.

Question 9 options:

B obj1 = new A();

A ob1 = new A();

B obj1 = new B();

A obj1 = new B();

Question 10

Interfaces differ from Abstract class because:

Question 10 options:

a class can implement many interfaces, but can only extend one abstract class

abstract classes create a hierarchy but interfaces do not

interfaces can only contain abstract methods and no implementations

all of the above

Question 11

Given this code snippet,

what will this program print?

Question 11 options:

This code causes an error.

Mike
Mike
Bob

Bob
Mike
Mike

Bob

Bob
Mike
Bob

Question 12

Based on this code snippet

what does this program output?

Question 12 options:

Shape Rectangle Rectangle Circle

Shape Shape Shape Shape

Shape Shape Shape Circle

This code will error

Shape Rectangle Square Circle

Shape Rectangle Rectangle Oval

Explanation / Answer

Question 1 Answer) False
Explanation:- derived classes have a "is-a" relationship

Question 2 Answer) False
Explanation:- A class can be used as a superclass any number of times

Question 3 Answer) True

Question 4 Answer) the public instance methods of the superclass

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