Question 1

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

Accepted Answer

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

Question 2

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. B

Question 3

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) 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) Collections discourage software reuse because they are non-portable. 
D) Collections are carefully constructed for rapid execution and efficient use of memory. C

Question 4

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 5

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 6

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 7

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 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) 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 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

__________ 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 12

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 13

A Properties object is a __________ Hashtable object.

Accepted Answer

A) transient. 
B) persistent. 
C) polymorphic. 
D) protected. 
A) transient. 
B) persistent. 
C) polymorphic. 
D) protected.

Question 14

If the desired Object is not found,binarySearch returns __________.

Accepted Answer

A) a positive value 
B) zero 
C) a negative value 
D) an ObjectNotFoundError. 
A) a positive value 
B) zero 
C) a negative value 
D) an ObjectNotFoundError.

Question 15

Which of these is not an example of a "real-life" collection?

Accepted Answer

A) The cards you hold in a card game. 
B) Your favorite songs stored in your computer. 
C) The players on a soccer team. 
D) The number of pages in a book. 
A) The cards you hold in a card game. 
B) Your favorite songs stored in your computer. 
C) The players on a soccer team. 
D) The number of pages in a book.

Question 16

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 17

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.

Question 18

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

Question 19

Interface Collection contains __________ operations (i.e.,operations performed on the entire collection).

Accepted Answer

A) aggregate. 
B) composite. 
C) integral. 
D) bulk. 
A) aggregate. 
B) composite. 
C) integral. 
D) bulk.

Question 20

Java supports type inferencing with the <> notation in statements that declare and create generic type variables and objects.For example,the following line: List list = new ArrayList(); Can be written as:

Accepted Answer

A) List<> list = new ArrayList<>(); B) List<> list = new ArrayList(); C) List list = new ArrayList<>(); D) List list = new ArrayList(); A) List<> list = new ArrayList<>(); B) List<> list = new ArrayList(); C) List list = new ArrayList<>(); D) List list = new ArrayList();

Exam 16: Generic Collections

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

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

Which statement is false?

Which statement is false?

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

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

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

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

Which statement is false?

Algorithm __________ randomly orders a List's elements.

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

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

A Properties object is a __________ Hashtable object.

If the desired Object is not found,binarySearch returns __________.

Which of these is not an example of a "real-life" collection?

LinkedList method listIterator returns a(n)__________.

Which statement is false?

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

Interface Collection contains __________ operations (i.e.,operations performed on the entire collection).

Java supports type inferencing with the <> notation in statements that declare and create generic type variables and objects.For example,the following line: List<String> list = new ArrayList<String>(); Can be written as:

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

Gui Components: Part 1

Graphics and Java 2D

Strings

Files,streams and Object Serialization

Lambdas

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

Concurrency

Accessing Databases With Jdbc

JavaFX

Filters