Exam 1

Question 1

public class HelloPrinter

What is the access specifier

Answer 1

public

Question 2

public class HelloPrinter

What is the class keyword

Answer 2

class

Question 3

public class HelloPrinter

What is the class name

Answer 3

HelloPrinter

Question 4

What is the code to create a main Method

Answer 4

public static void main(String[] args)
{

}

Question 5

public static void main(String[] args)
{

}

What is the access specifier

Answer 5

public

Question 6

public static void main(String[] args)
{

}

What is the return type

Answer 6

void

Question 7

public static void main(String[] args)
{

}

What is the method name

Answer 7

main

Question 8

public static void main(String[] args)
{

}

What is the parameter

Answer 8

(String[] args)

Question 9

Scanner class can be used for input from the ___________

Answer 9

Keyboard

Question 10

What’s the code to import a scanner class

Answer 10

import java.util.Scanner;

Question 11

Code to declare a scanner object

Answer 11

Scanner scan = new Scanner(System.in);

Question 12

Name the scanner methods

Answer 12

nextLine()
nextInt()
nextDouble()

No nextbooleans or nextchar

Question 13

A class describes a set of objects with the _______ behavior

Answer 13

Same

Question 14

Which of the following are legal identifiers?

Greeting1
g
void
101dalmations
Hello, World

Answer 14

Only the first two

Question 15

What is the output:

String greeting = “Hello, World!”;
System.out.println(greeting.length());

Answer 15

13

Question 16

________ method replaces ALL instances of a substring in a string with a new substring

Answer 16

replace

Question 17

What is the output

String river = “Mississippi”;

river = river.replace(“issipp”, “our”);

System.out.println(river);

Answer 17

Missouri

Question 18

String river = “Mississippi”;

Is it legal to call river.println(); ? Why or why not?

Answer 18

Not legal. Variable river has type string.

println method is not a method of the String class

Question 19

What are the steps in writing a tester class

Answer 19

1. Provide a tester class
2. Supply a main method
3. Inside the main method, construct one or more objects.
4. Apply methods to the objects.
5. Display the results of the methods calls.
6. Display the values that you expect to get.

Question 20

An ________________ is a variable whose data type is a class.

Answer 20

Object variable

Question 21

An object variable does _____ actually hold and object.

Answer 21

Not

Question 22

An object variation holds the ___________ of an object

Answer 22

Memory location

Question 23

Multiple object variables can refer to the ________ object

Answer 23

Same

Question 24

Numbers are _____ objects

Answer 24

Not

Question 25

Number variables actually ____________

Answer 25

Store numbers

Question 26

When you copy a number, the original and the copy of the number are _______________

Answer 26

Independent values

Question 27

When you copy an object reference both the original and the copy are references to the _________

Answer 27

Same object

Question 28

Start the comment with a

Answer 28

/**

Question 29

Omit _______ tag for methods that have no arguments

Answer 29

@param

Question 30

Omit the _________ tag for methods whose return type is void

Answer 30

@return

Question 31

End a comment with

Answer 31

*/

Question 32

API

Answer 32

Application programming interface

Question 33

Lists classes and methods of the java library

Answer 33

API documentation

Question 34

A programmer who uses the java classes to put together a computer program (or application)

Answer 34

Application programmer

Question 35

A programmer who designs and implements library classes such as PrintStream and Rectangle

Answer 35

Systems programmer

Question 36

Once you create your own _________, you can no longer use Java’s default constructor

This is true whether you create a ___________ constructor, and _________ constructor, both types, of more than 2 constructors

Answer 36

Constructor

No-argument
Argument

Question 37

_______________ store data of an object

Answer 37

Instance variable

Question 38

_____________ is an object of the class

Answer 38

Instance of a class

Question 39

An ____________ is a storage location in each object created from a class

Answer 39

Instance variable

Question 40

The ____________ specifies the instance variables

Answer 40

Class declaration

Question 41

An objects instance variables store the ________ requires for executing its methods

Answer 41

Data

Question 42

An ________________________ consists of the following parts:

Access specifier
Type of variable
Name of variable

Answer 42

Instance variable declaration

Question 43

An instance variable declaration consists of:

Answer 43

Access specifier (such as private)
Type of variable(such as int)
Name of variable(such as value)

Question 44

You should declare all instance variables as ____________

Answer 44

Private

Question 45

Each object of a class has __________ of instance variables

Answer 45

It’s own set

Question 46

The ________________:

Terminated the method call
Returns a result to the methods called

Answer 46

Return statement

Question 47

Affects the value of the ______________ of an object on which the method is invoked

Answer 47

Instance variable

Question 48

___________ instance variables can ______ be accesses by methods of the ______ class

Answer 48

Private
Only
Same

Question 49

What is encapsulation?

Answer 49

Process of hiding implementation details and providing methods for data access

Question 50

How to encapsulate data?

Answer 50

Declare instance variables as PRIVATE

declare PUBLIC methods that access the variable

Question 51

_________ allows a programmer to use a class without having to know its implementation

Answer 51

Encapsulation

Question 52

Information hiding makes it simpler for the implementer of a class to?

Answer 52

Locate errors and change implementations

Question 53

In order to implement a class, you first?

Answer 53

Need to know which methods are required

Question 54

A methods ______ consisting of statements that are executed when the method is called:

Answer 54

Body

Question 55

Public methods can be called by __________ in the entire program

Answer 55

All other methods

Question 56

Private methods can only be called by ____________________

Answer 56

Other methods in the same class

Question 57

Private methods are _____ part of the public interface

Answer 57

Not

Question 58

The name of the constructor is always the _________ as the name of the class

Answer 58

Same

Question 59

Constructors have _____ return type

Answer 59

No

Question 60

The constructor name is ________ the same as the class name

Answer 60

Always

Question 61

A constructor that takes no arguments is called a __________________

Answer 61

No-argument constructor

Question 62

Public constructors and methods of a class form the _____________ of the class

Answer 62

Interface

Question 63

The _________________ of a class consists of:

Private instance variables
The bodies of constructors
The bodies of methods

Answer 63

Private implementation

Question 64

What does the private implementation of a class consist of?

Answer 64

Private instance variable
The bodies of constructors
The bodies of methods

Question 65

Constructors job is to __________ the instance variables of the object

Answer 65

Initialize

Question 66

What is the memory location of an object?

Answer 66

Object reference

Question 67

_________ update the instance variables in some way

Answer 67

Mutator or setter

Question 68

_______ retrieves or computes a result

Answer 68

Accessor or getter

Question 69

Updates the balance

Answer 69

Deposit method

Question 70

Updates the balance subtracting

Answer 70

Withdraw method

Question 71

An accessor method that returns the balance

Answer 71

getBalance

Question 72

Scope __________ are declared in the body of a method

Answer 72

Local variables

Question 73

Scope __________ are declared in the header of a method

Answer 73

Parameter variables

Question 74

Scope Local and parameter variables belong to _________

Answer 74

Methods

Question 75

Local and parameter in methods exits, they are _______________

Answer 75

Removed immediately

Question 76

Scope Instance variables belong to _________

Answer 76

Objects

Question 77

Instance variables are initialized to a _____________

Answer 77

Default value

Question 78

Default values of Object references are set to a special value called _____

Answer 78

Null

Question 79

Default value for numbers are

Answer 79

0

Question 80

A ______ object reference refers to no object at all

Answer 80

Bull

Question 81

You must _______ local variables

Answer 81

Initialize

Question 82

What happens if you do not initialize local variables

Answer 82

The compiler complains

Question 83

What do local variables and parameter variables have in common?

Answer 83

Belong to methods/ come alive when called

Both die the the method exits

Question 84

What aspect do local variables and parameter variables differ

Answer 84

Initialization

Parameter variables are initialized with the call value

Local variables much be explicitly initialized

Question 85

Two types of imputs are passed when ______ method is called:

The OBJECT on which you invoke the method

The method argument

Answer 85

This

Question 86

public void deposit(double amount)
{
balance = balance + amount;
}

What is the explicit parameter?

Answer 86

amount

Question 87

public void deposit(double amount)
{
balance = balance + amount;
}

The _________ parameter (momSavings) is not seen

Answer 87

Implicit

Question 88

When you reference to an instance variable inside a method, it means?

Answer 88

The instance variable of the implicit parameter

Question 89

The this reference denotes the _______________

Answer 89

Implicit parameter

Question 90

When you reference to an instance variable in a method, the compiler automatically applies it to the _____________

Answer 90

this reference

Question 91

A local variable ____________ an instance variable that has the same name

Answer 91

Shadows

Question 92

In java, local and parameter variables are considered _______ when looking up variable names

Answer 92

first

Question 93

A method call without the implicit parameter is applies to the _____________

Answer 93

Same object

Question 94

Why can’t BankAccount.java be executed?

Answer 94

No main method

Most classes do not have a main method

Question 95

BankAccount.java should be tester before using in a larger program in ___________

Answer 95

Isolation

Question 96

Verifies that a class works correctly in isolation, outside a complete program

Answer 96

Unit test

Question 97

A class with a main method that contains statements to test another class

Answer 97

Tester class

Question 98

Tester class typically carries out the following steps

Answer 98

1. Constructs object(s) that is being tested
2. Income one or more methods
3. Print out one or more results
4. Print the expected results