Question 1

__________ 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 2

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.

Question 3

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 4

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 5

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 6

Which statement about hashing is false?

Accepted Answer

A) Hashing facilitates high-speed storing and retrieval of data. 
B) Two different data items can hash to the same cell;this is called a collision. 
C) A load factor of 0.5 usually results in good hashing performance,but less efficient utilization of memory. 
D) A load factor of 1.0 usually results in good hashing performance,but less efficient utilization of memory. 
A) Hashing facilitates high-speed storing and retrieval of data. 
B) Two different data items can hash to the same cell;this is called a collision. 
C) A load factor of 0.5 usually results in good hashing performance,but less efficient utilization of memory. 
D) A load factor of 1.0 usually results in good hashing performance,but less efficient utilization of memory.

Question 7

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 8

Collections method ___________ returns a Comparator object that orders the collection's elements in reverse order.

Accepted Answer

A) rotate. 
B) shuffle. 
C) reverse. 
D) reverseOrder. 
A) rotate. 
B) shuffle. 
C) reverse. 
D) reverseOrder.

Question 9

Which statement is false?

Accepted Answer

A) A List is an ordered Collection. 
B) A List cannot contain duplicate elements. 
C) A List is sometimes called a sequence. 
D) Lists are zero based. 
A) A List is an ordered Collection. 
B) A List cannot contain duplicate elements. 
C) A List is sometimes called a sequence. 
D) Lists are zero based.

Question 10

Comparator method compare should return ________ if the first argument is greater than the second argument.

Accepted Answer

A) a positive int value. 
B) zero. 
C) a negative int value. 
D) a String. 
A) a positive int value. 
B) zero. 
C) a negative int value. 
D) a String.

Question 11

PriorityQueue method __________ inserts an element at the appropriate location in the queue.

Accepted Answer

A) offer. 
B) push. 
C) poll. 
D) peek. 
A) offer. 
B) push. 
C) poll. 
D) peek.

Question 12

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 13

Which statement is false?

Accepted Answer

A) A collection is an object that can hold references to other objects. 
B) The collection interfaces declare the operations that can be performed on each type of collection. 
C) Unfortunately,collections discourage software reuse because they are non-portable. 
D) Collections are carefully constructed for rapid execution and efficient use of memory. 
A) A collection is an object that can hold references to other objects. 
B) The collection interfaces declare the operations that can be performed on each type of collection. 
C) Unfortunately,collections discourage software reuse because they are non-portable. 
D) Collections are carefully constructed for rapid execution and efficient use of memory.

Question 14

Class Collections provides algorithms for reversing,filling and copying ________.

Accepted Answer

A) Lists. 
B) Collections. 
C) Arrays. 
D) Stacks. 
A) Lists. 
B) Collections. 
C) Arrays. 
D) Stacks.

Question 15

Maps allocate keys to values and cannot contain duplicate keys,i.e. ,the key-to-value mapping is a __________ mapping.

Accepted Answer

A) many-to-many. 
B) many-to-one. 
C) one-to-many. 
D) one-to-one. 
A) many-to-many. 
B) many-to-one. 
C) one-to-many. 
D) one-to-one.

Question 16

Which of the following does not implement interface List?

Accepted Answer

A) ArrayList. 
B) LinkedList. 
C) Vector. 
D) ListIterator. 
A) ArrayList. 
B) LinkedList. 
C) Vector. 
D) ListIterator.

Question 17

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 18

Stack method __________ looks at the top element of a stack without removing that element.

Accepted Answer

A) glance. 
B) peek. 
C) look. 
D) sample. 
A) glance. 
B) peek. 
C) look. 
D) sample.

Question 19

Collections method sort that accepts a List as an argument sorts the elements of a List,which must implement the __________ interface.

Accepted Answer

A) Comparable. 
B) Comparator. 
C) Compare. 
D) Ordering. 
A) Comparable. 
B) Comparator. 
C) Compare. 
D) Ordering.

Question 20

Which statement is false?

Accepted Answer

A) Java does not guarantee which item will be found first when a binarySearch is performed on a List containing multiple elements equivalent to the search key. 
B) If the search key is found,method binarySearch returns the List index (position relative to 1)of the element containing the search key. 
C) The binary search algorithm is fast. 
D) Method binarySearch takes a List as the first argument. 
A) Java does not guarantee which item will be found first when a binarySearch is performed on a List containing multiple elements equivalent to the search key. 
B) If the search key is found,method binarySearch returns the List index (position relative to 1)of the element containing the search key. 
C) The binary search algorithm is fast. 
D) Method binarySearch takes a List as the first argument.

Exam 20: Generic Collections

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

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

Which statement is false?

Which statement is false?

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

Which statement about hashing is false?

Which of the following performs a boxing conversion?

Collections method ___________ returns a Comparator object that orders the collection's elements in reverse order.

Which statement is false?

Comparator method compare should return ________ if the first argument is greater than the second argument.

PriorityQueue method __________ inserts an element at the appropriate location in the queue.

Method shuffle is a member of __________.

Which statement is false?

Class Collections provides algorithms for reversing,filling and copying ________.

Maps allocate keys to values and cannot contain duplicate keys,i.e. ,the key-to-value mapping is a __________ mapping.

Which of the following does not implement interface List?

Iterator method __________ determines whether the Collection contains more elements.

Stack method __________ looks at the top element of a stack without removing that element.

Collections method sort that accepts a List as an argument sorts the elements of a List,which must implement the __________ interface.

Which statement is false?

Introduction to Computers and Java

Introduction to Java Applications

Introduction to Classes and Objects

Control Statements: Part 1

Control Statements: Part 2

Methods: a Deeper Look

Arrays and Arraylists

Classes and Objects: a Deeper Look

Object Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism

Exception Handling

Atm Case Study,part 1: Object-Oriented Design With the Uml

Atm Case Study,part 2: Implementing an Object-Oriented Design

Gui Components: Part 1

Graphics and Java 2d

Strings

Files,streams and Object Serialization

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

Applets and Java Web Start

Multimedia: Applets and Applications

Gui, Part 2

Multithreading

Networking

Accessing Databases With Jdbc

Java Server Faces Web Applications

Ajax-Enabled Jsf Web Applications

Web Services

Filters