Java SE 11: Objects & Classes

Question 1

Answer 1

Behavior

C D

Property

A B E

Question 2

Answer 2

A Noun

B Adjective

C Verb

Question 3

Given the following code, select the answers which best describe the type of variable alice.

Customer alice = new Customer( );

▢ Object reference

▢ Reserved world

▢ Class

▢ Primitive type

▢ Reference variable

Answer 3

√ Object reference

Reserved world

Class

Primitive type

√ Reference variable

Question 4

Given the analogy of a remote to control a camera, what does this describe in Java?

• How objects are accessed using object references
• How multiple objects can represent Java objects
• How objects consist of properties and operations
• How objects are created or instantiated by their class type

Answer 4

How objects are accessed using object references

Question 5

Select the necessary condition for a variable to reference an object.

You need a copy of the instantiated class

You need to use the remote keyword

You need a variable reference of the correct type

You need a universal variable

Answer 5

You need a variable reference of the correct type

Answer 6

Question 7

What should be the output of the following code snippet?

Shirt myShirt = new Shirt();
Shirt yourShirt = new Shirt();

myShirt = yourShirt;
myShirt.colorCode = 'R';
yourShirt.colorCode = 'G';

System.out.println(myShirt.colorCode);

myShirt

G

R

yourShirt

Answer 7

G

Question 8

Select the answer which describes how Java arrays are stored in memory.

Memory addresses on the heap

Primitive elements on the stack

Object stored on the heap

Object references on the stack

Answer 8

Object stored on the heap

Question 9

What keyword is used to invoke a constructor?

new

object

class

public

construct

Answer 9

new

Question 10

What return type is specified by a constructor method?

New

Class

Public

No type is specific

Answer 10

No type is specific

Question 11

What is a value passed into a method called?

Parameter

Class

Argument

Object reference

Answer 11

Argument

Question 12

Given a function that specifies a return type of void, what will it return?

A class

A void reference

Nothing

An object reference

Answer 12

Nothing

Question 13

Select the elements that make up a method signature.

▢ Number parameters

▢ Modifier

▢ Parameter types

▢ Method name

▢ Return type

▢ Order of parameters

Answer 13

√ Number parameters

▢ Modifier

√ Parameter types

√ Method name

▢ Return type

√ Order of parameters

Question 14

Given the following code, what is the scope of the price field?

public class Shirt {

public String description;

public char colorCode;

public double price;

public void setPrice(double thePrice) {

price = thePrice;

}

public double getPrice() {

return price;

}

The global application

The Shirt class

The setPrice method

The getPrice method

Answer 14

The Shirt class

Question 15

Devide section by Class name, Fields and Methods.

Answer 15

Question 16

What’s the difference between declaring an object and instatiating an object

Answer 16

No value is assigned when an object is just declared.

Initialization is the assignment of a value to a variable at the time of declaration.

Question 17

what is the . operator for?

Answer 17

The period . operator is used to access the fields and methods of an object.

Question 18

In java you access objects using ________

Answer 18

references

Question 19

Objects are created or ________ by their class type.

Answer 19

instantiated

Question 20

Any object consist of properties and operations, which we call _____ and ______ in Java

Answer 20

Any object consist of properties and operations, which we call fields and methods in Java

Question 21

References point to a particular object in _____

Answer 21

memory

Question 22

In this snippet of code we have three variables:

int counter = 10

Shirt myShirt = new Shirt

Shirt yourShirt = new Shirt.

How many objects end up in memory?

Answer 22

Two objects in memory

Question 23

A primitive type int is stored as an object.

True or False

Answer 23

False

Question 24

A primitive type int is stored as a _______.

Answer 24

variable

Question 25

Variable types and references are store in the _____

Answer 25

stack

Question 26

Object types are store in the _____

Answer 26

Heap

Question 27

The stack holds local variables, either ______ or _______ ____

Answer 27

The stack holds local variables, either primitives or reference types

Question 28

What happens if you assign an existing reference to another reference?

Answer 28

The existing reference will drop it’s current object and re-assigned to the same object of the new reference.

Question 29

An array is actually an _____ type and is handled implicitly through an internal class in Java called _____.

Answer 29

An array is actually an object type and is handled implicitly through an internal class in Java called Array.

Question 30

Like other object types with string being an exception, an array must be instantiated using the ___ keyword

Answer 30

Like other object types with string being an exception, an array must be instantiated using the new keyword

int[] ages = new int [4];

exception: int[] ages = { 8, 7, 5, 3 };

Question 31

Arrays are _____ in memory that are referred to by an object _____ _____

Answer 31

Arrays are objects in memory that are referred to by an object reference variable

Question 32

The public keyword is a _____

Answer 32

The public keyword is a _____

Question 33

____ is a keyword that indicates that the method does not return a value

Answer 33

void is a keyword that indicates that the method does not return a value

Question 34

The _____/_____ method is the main method or a method that calls another method to do work.

Answer 34

The caller /calling method is the main method or a method that calls another method to do work.

Question 35

A __________ ______ is a special method that is invoked when you create an object instance

Answer 35

A Contrustor Method is a special method that is invoked when you create an object instance

Question 36

A constructor method is called by using the ___ keyword.

Answer 36

new

Shirt myShirt = new Shirt ( )

Question 37

The _____ _______ is the unique combination of a method’s name, the number, types, and order of its parameters.

Answer 37

The Method Signature is the unique combination of a method’s name, the number, types, and order of its parameters.

public double add (double x, double y)

public int add (int x, int y)

Question 38

The method signature does not include the _____ ____

Answer 38

return type

Question 39

So the _____ of a variable determines where you can access the variable and for how long you can count on its value to persist.

Answer 39

So the scope of a variable determines where you can access the variable and for how long you can count on its value to persist.

Question 40

A variable is usually called a _____ when it’s in a class

Answer 40

field

Question 41

Instance variables or fields are stored in the long term memory ____

Answer 41

Instance variables or fields are stored in the long term memory heap

Question 42

An instance variable is accessible from any code within this ____

Answer 42

class

Question 43

Local variables are stored in the ____

Answer 43

stack

Question 44

A local variable is ______ from ______ when the method ends

Answer 44

A local variable is deleted from memory when the method ends

Question 45

A ____ _____ in Java is a variable that’s declared within the body of a method.

Answer 45

local variable

Question 46

______ _________ is a feature that allows a class to have more than one method having the same name, if their ______ lists are different

Answer 46

Method Overloading is a feature that allows a class to have more than one method having the same name, if their argument lists are different

add(int, int)

add(int, int, int)

add(int, float)

add(float, int)

Question 47

A ____, in the context of Java, are templates that are used to create objects, and to define object data types and methods. Core properties include the data types and methods that may be used by the object

Answer 47

class