Deck 6: Introduction to Defining Classes

Question 1

The combining of data and behavior into a single software package is called ____.

A) instantiation
B) modification
C) encapsulation
D) identification

Answer 1

C

Question 2

A constructor method indicates how to initialize a new object.

Answer 2

True

Question 3

When a Java program is executing, memory for data is allocated within objects.

Answer 3

True

Question 4

A class template can include more than one constructor, provided each has a unique parameter list.

Question 5

When a new class is created, it includes the characteristics of its superclass through a process called inheritance. ____________________

Question 6

A variable of a primitive type is thought of as a box that contains a pointer to an object. ____________________

Question 7

A(n) ____ is a runtime entity that contains data and responds to messages.

A) object
B) class
C) package
D) method

Question 8

The process of creating a new object is called ____.

A) instantiation
B) modification
C) encapsulation
D) identification

Question 9

Finding run-time errors in a program is more difficult when there are several classes instead of just one.

Question 10

Java programmers must instruct the program to delete objects explicitly.

Question 11

The purpose of a message is to pass information to a method.

Question 12

Class definitions usually begin with the keyword private.

Question 13

When sending messages, a client only needs to know the server's identity. ____________________

Question 14

When a Java program is executing, the computer's memory is holding all of the following EXCEPT ____.

A) all class templates in their compiled form
B) an object's state
C) variables that refer to objects
D) objects as needed

Question 15

An argument is a value passed to a method when it is invoked. ____________________

Question 16

In the hierarchy of Java classes, if class A is immediately above class B, A is the subclass or child of class B.

Question 17

An object has ____, as defined by the methods of its class.

A) state
B) identity
C) scope
D) behavior

Question 18

Shadowing is when a local variable and an instance variable have the same name.

Question 19

Do not use a variable until you have assigned its initial value.

Question 20

An object must have its own unique identity, which distinguishes it from all other objects in the computer's memory. ____________________

Question 21

In the code ____, i and j are memory locations that have not yet been initialized, but which will hold integers.

A) i = int; j = int;
B) int i, j;
C) int = i, j;
D) i = ?; j = ?;

Question 22

FIGURE 6-2
In Figure 6-2 above, the program ____.

A) is executing
B) has a run-time error
C) is showing its output
D) is compiling

Question 23

In a method, the return type should be ____ when the method returns no value.

A) void
B) null
C) 0
D) { }

Question 24

All of the following are true about constructors, EXCEPT ____.

A) if a class has more than one constructor, all of the constructors must have the same name
B) if a class template contains no constructors, the JVM provides a primitive default constructor
C) a class is harder to use when it has a variety of constructors
D) all of the above are true

Question 25

When a class includes several constructors, the code for them can be simplified by ____ them.

A) defining
B) combining
C) instantiating
D) chaining

Question 26

A(n) ____________________ is a description of a task that is performed in response to a message.

Question 27

All classes have a similar structure, consisting of all of the below parts EXCEPT ____.

A) the class's name and some modifying phrases
B) a description of the instance variables
C) one or more constructor methods
D) methods that specify how an object responds to variables

Question 28

____ is used to set up a skeletal, incomplete, but running program during program development.

A) { }
B) A stub
C) A placeholder
D) A helper method

Question 29

A(n) ____________________ is a software package or template that describes the characteristics of similar objects.

Question 30

It is the role of ____ to contain data and to respond to messages.

A) packages
B) methods
C) classes
D) objects

Question 31

An object has ____________________, which is another way of saying that at any particular moment its instance variables have particular values.

Question 32

A program can detect and respond to mouse events by attaching ____ objects to a panel.

A) clicker
B) listener
C) button
D) helper

Question 33

Messages that change an object's state are called ____________________.

Question 34

Defining a(n) ____ for a shape allows a user to manipulate it by changing its color, position, or size.

A) class
B) object
C) parameter
D) method

Question 35

Parameters listed in a method's definition are called ____ parameters.

A) header
B) actual
C) formal
D) argument

Question 36

The ____ of a variable is the region of the program within which it can validly appear in lines of code.

A) lifetime
B) block
C) scope
D) parameter

Question 37

In the hierarchy of Java classes, at the root of the hierarchy is a class called ____.

A) Object
B) Child
C) Base
D) Subclass

Question 38

Ana tells Pratik that a circle's attributes include all of the following EXCEPT ____.

A) color
B) circumference
C) center point
D) radius

Question 39

FIGURE 6-1
Figure 6-1 above shows the Student variable before and after it has been assigned the value ____.

A) void
B) 0
C) null
D) \

Question 40

Variables declared within any compound statement enclosed in braces are said to have ____ scope.

A) initial
B) infinite
C) local
D) block

Question 41

Identify the letter of the choice that best matches the phrase or definition.
a.Garbage collection
b.Reference type
c.Public
d.Information hiding
e.Helper method
When the server's data requirements and the implementation of its methods are concealed from the client.

Question 42

Identify the letter of the choice that best matches the phrase or definition.
a.Garbage collection
b.Reference type
c.Public
d.Information hiding
e.Helper method
A process in which unreferenced objects are removed from memory.

Question 43

Identify the letter of the choice that best matches the phrase or definition.
a.Garbage collection
b.Reference type
c.Public
d.Information hiding
e.Helper method
Includes String, Student, Scanner, and other classes.

Question 44

Identify the letter of the choice that best matches the phrase or definition.
a.Garbage collection
b.Reference type
c.Public
d.Information hiding
e.Helper method
Used when a task is broken into subtasks.

Question 45

Identify the letter of the choice that best matches the phrase or definition.
a.Garbage collection
b.Reference type
c.Public
d.Information hiding
e.Helper method
A type of visibility modifier.

Question 46

A(n) ____________________ variable is declared in order to have temporary working storage for data in a method.