Question 1

Which of the following performs an unboxing conversion? Assume x refers to an Integer object.

Accepted Answer

A)  int y = x; 
B)  Integer y = x; 
C)  Neither of the above. 
D)  Both of the above. 
A)  int y = x; 
B)  Integer y = x; 
C)  Neither of the above. 
D)  Both of the above. A

Question 2

Map method ________ is used to determine whether a map contains a mapping for the specified key.

Accepted Answer

A)  containsKey 
B)  hasKey 
C)  containsMapping 
D)  hasMapping 
A)  containsKey 
B)  hasKey 
C)  containsMapping 
D)  hasMapping A

Question 3

Objects of many classes can now be output and input with Java's object __________.

Accepted Answer

A)  encapsulation. 
B)  overloading. 
C)  serialization. 
D)  reflection. 
A)  encapsulation. 
B)  overloading. 
C)  serialization. 
D)  reflection. C

Question 4

The collections framework algorithms are __________, i.e., each of these algorithms can operate on objects that implement specified interfaces without concern for the underlying implementations.

Accepted Answer

A)  stable. 
B)  lexicographical. 
C)  polymorphic. 
D)  implementation dependent. 
A)  stable. 
B)  lexicographical. 
C)  polymorphic. 
D)  implementation dependent.

Question 5

Which statement is false?

Accepted Answer

A)  All built-in collections are synchronized. 
B)  Concurrent access to a Collection by multiple threads could cause indeterminate results or fatal errors. 
C)  To prevent potential threading problems, synchronization wrappers are used around collection classes that might be accessed by multiple threads. 
D)  A synchronization wrapper class receives method calls, adds some functionality for thread safety and then delegates the calls to the wrapped class. 
A)  All built-in collections are synchronized. 
B)  Concurrent access to a Collection by multiple threads could cause indeterminate results or fatal errors. 
C)  To prevent potential threading problems, synchronization wrappers are used around collection classes that might be accessed by multiple threads. 
D)  A synchronization wrapper class receives method calls, adds some functionality for thread safety and then delegates the calls to the wrapped class.

Question 6

Iterator method __________ determines whether the Collection contains more elements.

Accepted Answer

A)  hasNext. 
B)  next. 
C)  contains. 
D)  containsNext. 
A)  hasNext. 
B)  next. 
C)  contains. 
D)  containsNext.

Question 7

__________ methods enable a program to view a portion of a collection.

Accepted Answer

A)  Focus-view. 
B)  Range-view. 
C)  Delimiter-view. 
D)  Subset-view. 
A)  Focus-view. 
B)  Range-view. 
C)  Delimiter-view. 
D)  Subset-view.

Question 8

If no elements are in the Stack, method pop throws an __________.

Accepted Answer

A)  OutOfMemoryError. 
B)  OutOfMemoryException. 
C)  EmptyStackError. 
D)  EmptyStackException. 
A)  OutOfMemoryError. 
B)  OutOfMemoryException. 
C)  EmptyStackError. 
D)  EmptyStackException.

Question 9

Which statement is false?

Accepted Answer

A)  Queue is a new collection interface introduced in J2SE 5.0. 
B)  Queue and PriorityQueue are included in the java.util package. 
C)  PriorityQueue orders elements in increasing order, so that smallest value will be the first element removed from PriorityQueue. 
D)  Queue extends interface Collection. 
A)  Queue is a new collection interface introduced in J2SE 5.0. 
B)  Queue and PriorityQueue are included in the java.util package. 
C)  PriorityQueue orders elements in increasing order, so that smallest value will be the first element removed from PriorityQueue. 
D)  Queue extends interface Collection.

Question 10

Algorithm __________ randomly orders a List's elements.

Accepted Answer

A)  randomShuffle. 
B)  randomPlacement. 
C)  fiftyTwoCardPickup. 
D)  shuffle. 
A)  randomShuffle. 
B)  randomPlacement. 
C)  fiftyTwoCardPickup. 
D)  shuffle.

Question 11

LinkedList method listIterator returns a(n) __________.

Accepted Answer

A)  Iterator. 
B)  List. 
C)  sub list. 
D)  bidirectional iterator. 
A)  Iterator. 
B)  List. 
C)  sub list. 
D)  bidirectional iterator.

Question 12

Which of the following is not an abstract implementation provided by the collections framework?

Accepted Answer

A)  AbstractCollection. 
B)  AbstractTree. 
C)  AbstractMap. 
D)  AbstractList. 
A)  AbstractCollection. 
B)  AbstractTree. 
C)  AbstractMap. 
D)  AbstractList.

Question 13

Method shuffle is a member of __________.

Accepted Answer

A)  class Arrays. 
B)  class Collections. 
C)  interface Collection. 
D)  Interface List. 
A)  class Arrays. 
B)  class Collections. 
C)  interface Collection. 
D)  Interface List.

Question 14

Which statement is false?

Accepted Answer

A)  SortedSet extends Set. 
B)  Class SortedSet implements TreeSet. 
C)  When a HashSet is constructed, it removes any duplicates in the Collection. 
D)  By definition, a Set object does not contain any duplicates. 
A)  SortedSet extends Set. 
B)  Class SortedSet implements TreeSet. 
C)  When a HashSet is constructed, it removes any duplicates in the Collection. 
D)  By definition, a Set object does not contain any duplicates.

Question 15

The classes and interfaces which comprise the collections framework are members of package ________.

Accepted Answer

A)  java.util. 
B)  javax.swing. 
C)  java.collections. 
D)  java.collection. 
A)  java.util. 
B)  javax.swing. 
C)  java.collections. 
D)  java.collection.

Question 16

Collections method __________ returns true if two Collections have no elements in common.

Accepted Answer

A)  shuffle. 
B)  contains. 
C)  hasCommon. 
D)  disjoint. 
A)  shuffle. 
B)  contains. 
C)  hasCommon. 
D)  disjoint.

Question 17

Which statement is false?

Accepted Answer

A)  Each primitive type has a corresponding type-wrapper class. 
B)  The type-wrapper classes enable you to manipulate primitive-type values as objects. 
C)  Type-wrapper classes are final, so you cannot extend them. 
D)  The methods for primitive types correspond to the methods for the corresponding type-wrapper classes. 
A)  Each primitive type has a corresponding type-wrapper class. 
B)  The type-wrapper classes enable you to manipulate primitive-type values as objects. 
C)  Type-wrapper classes are final, so you cannot extend them. 
D)  The methods for primitive types correspond to the methods for the corresponding type-wrapper classes.

Question 18

Which of the following performs a boxing conversion?

Accepted Answer

A)  int x = 7; 
B)  Integer x = 7; 
C)  Neither of the above. 
D)  Both of the above. 
A)  int x = 7; 
B)  Integer x = 7; 
C)  Neither of the above. 
D)  Both of the above.

Question 19

The collections framework provides various __________ collection interfaces from which the programmer can quickly "flesh out" complete customized implementations.

Accepted Answer

A)  abstract. 
B)  concrete. 
C)  structured. 
D)  unstructured. 
A)  abstract. 
B)  concrete. 
C)  structured. 
D)  unstructured.

Question 20

To find the smallest and largest element of a Collection, use Collections methods _________ and __________.

Accepted Answer

A)  least, greatest. 
B)  smallest, largest. 
C)  first, last. 
D)  min, max. 
A)  least, greatest. 
B)  smallest, largest. 
C)  first, last. 
D)  min, max.

Exam 16: Generic Collections

Which of the following performs an unboxing conversion? Assume x refers to an Integer object.

Map method ________ is used to determine whether a map contains a mapping for the specified key.

Objects of many classes can now be output and input with Java's object __________.

The collections framework algorithms are __________, i.e., each of these algorithms can operate on objects that implement specified interfaces without concern for the underlying implementations.

Which statement is false?

Iterator method __________ determines whether the Collection contains more elements.

__________ methods enable a program to view a portion of a collection.

If no elements are in the Stack, method pop throws an __________.

Which statement is false?

Algorithm __________ randomly orders a List's elements.

LinkedList method listIterator returns a(n) __________.

Which of the following is not an abstract implementation provided by the collections framework?

Method shuffle is a member of __________.

Which statement is false?

The classes and interfaces which comprise the collections framework are members of package ________.

Collections method __________ returns true if two Collections have no elements in common.

Which statement is false?

Which of the following performs a boxing conversion?

The collections framework provides various __________ collection interfaces from which the programmer can quickly "flesh out" complete customized implementations.

To find the smallest and largest element of a Collection, use Collections methods _________ and __________.

Introduction to Computers and Java

Introduction to Java Applications

Control Statements

Control Statements

Methods

Arrays and Arraylists

Introduction to Classes and Objects

Classes and Objects: a Deeper Look

Object Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism

Exception Handling

Gui Components

Graphics and Java 2D

Fundamentals of Characters and Strings

Files, Streams and Object Serialization

Lambdas

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

GUI

Concurrency

Accessing Databases With JDBC

JavaFX

Filters

To find the smallest and largest element of a Collection, use Collections methods _ and __.