Question 1

What can a generic class be parameterized for?

Accepted Answer

A) methods 
B) iterators 
C) type 
D) properties 
A) methods 
B) iterators 
C) type 
D) properties

Question 2

Consider the following code snippet:   What output will be produced when this code is executed?

Accepted Answer

A) ab,abc,a, 
B) abc,ab,a, 
C) a,abc,ab, 
D) a,ab,abc, 
A) ab,abc,a, 
B) abc,ab,a, 
C) a,abc,ab, 
D) a,ab,abc,

Question 3

When using a list iterator, on which condition will the IllegalStateException be thrown?

Accepted Answer

A) Calling next after calling previous. 
B) Calling remove after calling previous. 
C) Calling remove after calling remove. 
D) Calling remove after calling next. 
A) Calling next after calling previous. 
B) Calling remove after calling previous. 
C) Calling remove after calling remove. 
D) Calling remove after calling next.

Question 4

The ArrayList class implements the ____ interface.

Accepted Answer

A) Stack 
B) Queue 
C) List 
D) Set 
A) Stack 
B) Queue 
C) List 
D) Set

Question 5

Which data structure would best be used for storing a set of numbers and sorting them in ascending order?

Accepted Answer

A) queue 
B) array 
C) stack 
D) list 
A) queue 
B) array 
C) stack 
D) list

Question 6

Which method is NOT part of the ListIterator interface?

Accepted Answer

A) next 
B) delete 
C) add 
D) previous 
A) next 
B) delete 
C) add 
D) previous

Question 7

Assume that you have declared a stack named myStack to hold String elements.Which of the following statements will correctly remove an element from myStack?

Accepted Answer

A) myStack.delete(); 
B) myStack.pop(); 
C) myStack.remove(); 
D) myStack.get(); 
A) myStack.delete(); 
B) myStack.pop(); 
C) myStack.remove(); 
D) myStack.get();

Question 8

Which of the following statements about manipulating objects in a map is NOT correct?

Accepted Answer

A) Use the put method to add an element to the map. 
B) If you attempt to retrieve a value with a key that is not associated with any value, you will receive a null result. 
C) Use the get method to retrieve a value associated with a key in the map. 
D) You cannot change the value of an existing association in the map; you must delete it and re-add it with the new values. 
A) Use the put method to add an element to the map. 
B) If you attempt to retrieve a value with a key that is not associated with any value, you will receive a null result. 
C) Use the get method to retrieve a value associated with a key in the map. 
D) You cannot change the value of an existing association in the map; you must delete it and re-add it with the new values.

Question 9

To create a TreeSet for a class of objects, the object class must ____.

Accepted Answer

A) implement the Set interface. 
B) implement the Comparable interface. 
C) create an iterator. 
D) create a Comparator object. 
A) implement the Set interface. 
B) implement the Comparable interface. 
C) create an iterator. 
D) create a Comparator object.

Question 10

You need to access values by an integer position.Which collection type should you use?

Accepted Answer

A) Queue 
B) Map 
C) Hashtable 
D) ArrayList 
A) Queue 
B) Map 
C) Hashtable 
D) ArrayList

Question 11

When using a list iterator, on which condition will the NoSuchElementException be thrown?

Accepted Answer

A) Calling next when you are past the end of the list. 
B) Calling remove after calling add. 
C) Calling remove after calling previous. 
D) Calling next when the iterator points to the last element. 
A) Calling next when you are past the end of the list. 
B) Calling remove after calling add. 
C) Calling remove after calling previous. 
D) Calling next when the iterator points to the last element.

Question 12

A ____ is a data structure used for collecting a sequence of objects that allows efficient addition and removal of already-located elements in the middle of the sequence.

Accepted Answer

A) queue 
B) priority queue 
C) stack 
D) linked list 
A) queue 
B) priority queue 
C) stack 
D) linked list

Question 13

Consider the following code snippet:   What will this code print when it is executed?

Accepted Answer

A) abcdefghi 
B) defghiabc 
C) ghiabcdef 
D) abcghidef 
A) abcdefghi 
B) defghiabc 
C) ghiabcdef 
D) abcghidef

Question 14

You want to enumerate all of the keys in a map named myMap whose keys are type String.Which of the following statements will allow you to do this?

Accepted Answer

A) Set keySet = myMap.getKeySet(); for (String key : keySet) {...} B) Set keySet = myMap.keySet(); for (String key : keySet) {...} C) Set keySet = myMap.keys(); for (String key : keySet) {...} D) Set keySet = myMap.getKeys(); for (String key : keySet) {...} A) Set keySet = myMap.getKeySet(); for (String key : keySet) {...} B) Set keySet = myMap.keySet(); for (String key : keySet) {...} C) Set keySet = myMap.keys(); for (String key : keySet) {...} D) Set keySet = myMap.getKeys(); for (String key : keySet) {...}

Question 15

A collection that allows speedy insertion and removal of already-located elements in the middle of it is called a ____.

Accepted Answer

A) linked list 
B) stack 
C) set 
D) queue 
A) linked list 
B) stack 
C) set 
D) queue

Question 16

Which of the following correctly declares a stack that will hold String elements?

Accepted Answer

A) Stack s = new Stack<>(); B) Stack s = new Stack<>(); C) String s = new Stack(); D) String s = new Stack<>(); A) Stack s = new Stack<>(); B) Stack s = new Stack<>(); C) String s = new Stack(); D) String s = new Stack<>();

Question 17

Which operations from the list data structure could be used to implement the push and pop operations of a stack data structure?
i.addLast
II.addFirst
III.removeFirst

Accepted Answer

A) I and II only 
B) II and III only 
C) II only 
D) I only 
A) I and II only 
B) II and III only 
C) II only 
D) I only

Question 18

Assume that you have declared a map named myMap to hold String values with Integer keys.Which of the following statements will correctly delete an association from myMap?

Accepted Answer

A) myMap.remove(3); 
B) myMap.remove("apple"); 
C) myMap.delete(3); 
D) myMap.pop(3); 
A) myMap.remove(3); 
B) myMap.remove("apple"); 
C) myMap.delete(3); 
D) myMap.pop(3);

Question 19

Consider the following code snippet:   What output will be produced when this code is executed?

Accepted Answer

A) abc,ab,a, 
B) a,ab,abc, 
C) ab,abc,a, 
D) a,abc,ab, 
A) abc,ab,a, 
B) a,ab,abc, 
C) ab,abc,a, 
D) a,abc,ab,

Question 20

Your program uses a Map structure to store a number of user ids and corresponding email addresses.Although each user must have a unique id, two or more users can share the same email address.Assuming that all entries in the map have valid email addresses, select an appropriate expression to complete the method below, which adds a new id and email address to the map only if the id is not already in use.If the id is already in use, an error message is printed.

Accepted Answer

A) !currentEmail.equals(email) 
B) currentEmail.equals(email) 
C) currentEmail != null 
D) currentEmail == null 
A) !currentEmail.equals(email) 
B) currentEmail.equals(email) 
C) currentEmail != null 
D) currentEmail == null

Exam 15: The Java Collections Framework

What can a generic class be parameterized for?

Consider the following code snippet: What output will be produced when this code is executed?

When using a list iterator, on which condition will the IllegalStateException be thrown?

The ArrayList class implements the ____ interface.

Which data structure would best be used for storing a set of numbers and sorting them in ascending order?

Which method is NOT part of the ListIterator interface?

Assume that you have declared a stack named myStack to hold String elements.Which of the following statements will correctly remove an element from myStack?

Which of the following statements about manipulating objects in a map is NOT correct?

To create a TreeSet for a class of objects, the object class must ____.

You need to access values by an integer position.Which collection type should you use?

When using a list iterator, on which condition will the NoSuchElementException be thrown?

A ____ is a data structure used for collecting a sequence of objects that allows efficient addition and removal of already-located elements in the middle of the sequence.

Consider the following code snippet: What will this code print when it is executed?

You want to enumerate all of the keys in a map named myMap whose keys are type String.Which of the following statements will allow you to do this?

A collection that allows speedy insertion and removal of already-located elements in the middle of it is called a ____.

Which of the following correctly declares a stack that will hold String elements?

Which operations from the list data structure could be used to implement the push and pop operations of a stack data structure? i.addLast II.addFirst III.removeFirst

Assume that you have declared a map named myMap to hold String values with Integer keys.Which of the following statements will correctly delete an association from myMap?

Consider the following code snippet: What output will be produced when this code is executed?

Introduction

Using Objects

Implementing Classes

Fundamental Data Types

Decisions

Loops

Arrays and Array Lists

Designing Classes

Inheritance

Interfaces

Input/Output and Exception Handling

Object-Oriented Design

Recursion

Sorting and Searching

Basic Data Structures

Tree Structures

Generic Classes

Stream Processing

Graphical User Interfaces

Advanced Input/Output

Multithreading

Internet Networking

Relational Databases

XML

Filters