True/False
Indicate whether the sentence or statement is true
or false.
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1.
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When
a Java program is executing, the computer's memory must hold all class templates in their compiled
form, variables that refer to objects, and objects as needed.
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2.
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The
identity of an object is simply the variable that references the object.
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3.
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A
class's implementation details can be changed radically without affecting any of its clients provided
its interface remains the same.
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4.
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In
Java it is illegal to have two variables referencing the same object.
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5.
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The
keyword public indicates that the class is accessible to all potential clients.
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6.
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Constructors do not have return types, but all other methods do.
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7.
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A
class can include only one constructor.
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8.
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A
method can only have one return statement.
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9.
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Variables declared within any compound statement enclosed in braces are said to have
local scope.
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10.
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Global variables can be reused within several different methods without causing a
conflict.
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11.
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A
good way to provide temporary storage is to use global variables.
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12.
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When
using turtle graphics, the color of a pen cannot be changed.
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Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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13.
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The
process of creating a new object is called: a. | encapsulation | c. | instantiation | b. | class | d. | new | | | | |
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14.
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Java
deletes objects from memory in a process called: a. | deletion | c. | memory allocation | b. | garbage
collection | d. | memory
dumping | | | | |
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15.
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Which
characteristic of an object says that at any moment its instance variables have particular
values. a. | state
| c. | identity | b. | behavior | d. | instantiation | | | | |
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16.
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What
is the list of the methods supported by the server referred to as? a. | encapsulation | c. | behavior | b. | state | d. | interface | | | | |
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17.
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Messages that change an object's state are called: a. | accessors | c. | mutators | b. | constructors | d. | methods | | | | |
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18.
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What
is the name of a method that indicates how to initialize a new object? a. | initializer | c. | mutator | b. | constructor | d. | accessor | | | | |
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19.
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If
class A extends class B, class B is the _________ of class A. a. | parent | c. | nephew | b. | child | d. | subclass | | | | |
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20.
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If a
class A omits the extends <some class> clause, which class is assumed to be the
superclass of class A. a. | Object | c. | System | b. | KeyboardReader | d. | Math | | | | |
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21.
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What
are activated when the keyword new is used and at no other time. a. | accessors | c. | constructors | b. | mutators | d. | methods | | | | |
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22.
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A
method whose implementing code is omitted is called a: a. | accessor | c. | helper | b. | mutator | d. | stub | | | | |
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23.
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Values passed to a method when it is invoked are called: a. | actual
parameters | c. | constructors | b. | formal parameters | d. | initial values | | | | |
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24.
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To
provide temporary working storage for data in a method a programmer can declare: a. | global
variables | c. | instance
variables | b. | local variables | d. | classes | | | | |
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25.
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The
________ of a variable is that region of the program within which it can validly appear in lines of
code. a. | lifetime | c. | value | b. | type | d. | scope | | | | |
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26.
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Variables defined as instance variables of a class are referred to
as: a. | local | c. | temporary | b. | global | d. | public | | | | |
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27.
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The
_________ of a variable is the period during which it can be used. a. | time
period | c. | lifetime | b. | scope | d. | type | | | | |
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Completion
Complete each sentence or
statement.
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28.
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An
object has _________ as defined by the methods of its class.
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29.
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If a
reference variable of an object is set to _______, and no other variable points to that object, the
computer reclaims the object's memory during garbage collection.
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30.
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Using
the visibility modifier __________ for instance variables is an important aspect of information
hiding.
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31.
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Constructors with empty parameter lists are called ___________
constructors.
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32.
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Parameters listed in a method's definition are called ________
parameters.
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33.
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Methods that are usually private that help break down tasks to reduce complexity are
called _________ methods.
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34.
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A
programmer uses the symbol ______ to refer to the current instance of a class within that class's
definition.
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