Question 1

Which of the following statements is false?

Accepted Answer

A)  Prior to functional programming, you typically determined what you wanted to accomplish, then specified the precise steps to accomplish that task. 
B)  Using a loop to iterate over a collection of elements is known as external iteration and requires accessing the elements sequentially. Such iteration also requires mutable variables. External iteration is easier to parallelize. 
C)  Letting the library determine how to iterate over a collection of elements is known as internal iteration. 
D)  Functional programming focuses on immutability-not modifying the data source being processed or any other program state. 
A)  Prior to functional programming, you typically determined what you wanted to accomplish, then specified the precise steps to accomplish that task. 
B)  Using a loop to iterate over a collection of elements is known as external iteration and requires accessing the elements sequentially. Such iteration also requires mutable variables. External iteration is easier to parallelize. 
C)  Letting the library determine how to iterate over a collection of elements is known as internal iteration. 
D)  Functional programming focuses on immutability-not modifying the data source being processed or any other program state. B

Question 2

Stream mutable reduction operation ________creates an array containing the results of the stream's prior operations.

Accepted Answer

A)  array 
B)  createArray 
C)  toArray 
D)  reduceArray 
A)  array 
B)  createArray 
C)  toArray 
D)  reduceArray C

Question 3

________ is a method reference for an instance method of a class. It creates a one-parameter lambda that invokes the instance method on the lambda's argument and returns the method's result.

Accepted Answer

A)  Math::sqrt 
B)  System.out::println 
C)  TreeMap::new 
D)  String::toUpperCase 
A)  Math::sqrt 
B)  System.out::println 
C)  TreeMap::new 
D)  String::toUpperCase D

Question 4

Functional interface Comparator's default method ________ reverses an existing Comparator's ordering.

Accepted Answer

A)  invert 
B)  descending 
C)  reversed 
D)  downward 
A)  invert 
B)  descending 
C)  reversed 
D)  downward

Question 5

Which of the following statements is true?

Accepted Answer

A)  Stream method filter receives a Predicate and results in a stream of objects that match the Predicate. 
B)  Predicate method test returns a boolean indicating whether the argument satisfies a condition. 
C)  Interface Predicate also has methods and, negate and or. 
D)  Each of these statements is true. 
A)  Stream method filter receives a Predicate and results in a stream of objects that match the Predicate. 
B)  Predicate method test returns a boolean indicating whether the argument satisfies a condition. 
C)  Interface Predicate also has methods and, negate and or. 
D)  Each of these statements is true.

Question 6

The basic generic functional interface ________ in package java.util.function contains method get that takes no arguments and produces a value of type T. Often used to create a collection object in which a stream operation's results are placed.

Accepted Answer

A) Consumer B) Function C) Supplier D) BinaryOperator A) Consumer B) Function C) Supplier D) BinaryOperator

Question 7

The basic generic functional interface ________ in package java.util.function contains method test that takes a T argument and returns a boolean. Tests whether the T argument satisfies a condition.

Accepted Answer

A) Consumer B) Function C) Supplier D) Predicate A) Consumer B) Function C) Supplier D) Predicate

Question 8

An ________ (package java.util.stream) is a specialized stream for manipulating int values.

Accepted Answer

A)  StreamOfInt 
B)  IStream. 
C)  IntegerStream 
D)  IntStream 
A)  StreamOfInt 
B)  IStream. 
C)  IntegerStream 
D)  IntStream

Question 9

Which of the following statements is false?

Accepted Answer

A)  Functional interfaces must contain only one method and that method must be abstract. 
B)  When a class implements an interface with default methods and does not override them, the class inherits the default methods' implementations. An interface's designer can now evolve an interface by adding new default and static methods without breaking existing code that implements the interface. 
C)  If one class inherits the same default method from two interfaces, the class must override that method; otherwise, the compiler will generate a compilation error. 
D)  You can create your own functional interfaces by ensuring that each contains only one abstract method and zero or more default or static methods. 
A)  Functional interfaces must contain only one method and that method must be abstract. 
B)  When a class implements an interface with default methods and does not override them, the class inherits the default methods' implementations. An interface's designer can now evolve an interface by adding new default and static methods without breaking existing code that implements the interface. 
C)  If one class inherits the same default method from two interfaces, the class must override that method; otherwise, the compiler will generate a compilation error. 
D)  You can create your own functional interfaces by ensuring that each contains only one abstract method and zero or more default or static methods.

Question 10

Terminal Stream operation ________ performs processing on every element in a stream (e.g., display each element).

Accepted Answer

A)  forNext 
B)  for 
C)  forAll 
D)  forEach 
A)  forNext 
B)  for 
C)  forAll 
D)  forEach

Question 11

Intermediate operations are________; they aren't performed until a terminal operation is invoked. This allows library developers to optimize stream-processing performance.

Accepted Answer

A)  eager 
B)  idle 
C)  lazy 
D)  inactive 
A)  eager 
B)  idle 
C)  lazy 
D)  inactive

Question 12

________ is a constructor reference. It creates a lambda that invokes the no-argument constructor of the specified class to create and initialize a new object of that class.

Accepted Answer

A)  Math::sqrt 
B)  System.out::println 
C)  TreeMap::new 
D)  String::toUpperCase 
A)  Math::sqrt 
B)  System.out::println 
C)  TreeMap::new 
D)  String::toUpperCase

Question 13

Which statement in the following sequence of statements about sorting objects by two fields is false?

Accepted Answer

A)  To sort objects by two fields, you create a Comparator that uses two Functions. 
B)  First you call Comparator method comparing to create a Comparator with the first Function. 
C)  On the Comparator for the first field, you call method comparing with the second Function. 
D)  The resulting Comparator compares objects using the first Function then, for objects that are equal, compares them by the second Function. 
A)  To sort objects by two fields, you create a Comparator that uses two Functions. 
B)  First you call Comparator method comparing to create a Comparator with the first Function. 
C)  On the Comparator for the first field, you call method comparing with the second Function. 
D)  The resulting Comparator compares objects using the first Function then, for objects that are equal, compares them by the second Function.

Question 14

Functional interface BiConsumer's accept method has two parameters. For Maps, the first represents the ________ and the second the corresponding ________.

Accepted Answer

A)  key, variable 
B)  lambda, value 
C)  lambda, variable 
D)  key, value 
A)  key, variable 
B)  lambda, value 
C)  lambda, variable 
D)  key, value

Question 15

You can declare that an interface is a functional interface by preceding it with the @FunctionalInterface annotation. The compiler will then ensure that the interface contains ________; otherwise, it'll generate a compilation error.

Accepted Answer

A)  no abstract methods 
B)  all abstract methods 
C)  only one abstract method 
D)  one or more abstract methods. 
A)  no abstract methods 
B)  all abstract methods 
C)  only one abstract method 
D)  one or more abstract methods.

Question 16

A lambda expression represents a(n) ________ method-a shorthand notation for implementing a functional interface.

Accepted Answer

A)  functional 
B)  unnamed 
C)  undesignated 
D)  anonymous 
A)  functional 
B)  unnamed 
C)  undesignated 
D)  anonymous

Question 17

Which of the following statements is false?

Accepted Answer

A)  Interface IntPredicate's default method and performs a logical AND operation with short-circuit evaluation between the IntPredicate on which it's called and its IntPredicate argument. 
B)  Interface IntPredicate's default method invert reverses the boolean value of the IntPredicate on which it's called. 
C)  Interface IntPredicate default method or performs a logical OR operation with short-circuit evaluation between the IntPredicate on which it's called and its IntPredicate argument. 
D)  You can use the interface IntPredicate default methods to compose more complex conditions. 
A)  Interface IntPredicate's default method and performs a logical AND operation with short-circuit evaluation between the IntPredicate on which it's called and its IntPredicate argument. 
B)  Interface IntPredicate's default method invert reverses the boolean value of the IntPredicate on which it's called. 
C)  Interface IntPredicate default method or performs a logical OR operation with short-circuit evaluation between the IntPredicate on which it's called and its IntPredicate argument. 
D)  You can use the interface IntPredicate default methods to compose more complex conditions.

Question 18

Map method entrySet returns a Set of Map.Entry objects containing the Map's ________.

Accepted Answer

A)  values 
B)  keys 
C)  index 
D)  key-value pairs 
A)  values 
B)  keys 
C)  index 
D)  key-value pairs

Question 19

The type of a lambda is the type of the ________ that the lambda implements.

Accepted Answer

A)  anonymous class 
B)  functional interface 
C)  stream 
D)  collection 
A)  anonymous class 
B)  functional interface 
C)  stream 
D)  collection

Question 20

What is the meaning of ( ) in the following lambda?
() -> System.out.println("Welcome to lambdas!")

Accepted Answer

A)  the lambdas parameters are inferred 
B)  the lambdas parameters are supplied by a method reference 
C)  the lambda has an empty parameter list 
D)  the given expression is not a valid lambda 
A)  the lambdas parameters are inferred 
B)  the lambdas parameters are supplied by a method reference 
C)  the lambda has an empty parameter list 
D)  the given expression is not a valid lambda

Exam 17: Lambdas

Which of the following statements is false?

Stream mutable reduction operation ________creates an array containing the results of the stream's prior operations.

________ is a method reference for an instance method of a class. It creates a one-parameter lambda that invokes the instance method on the lambda's argument and returns the method's result.

Functional interface Comparator's default method ________ reverses an existing Comparator's ordering.

Which of the following statements is true?

The basic generic functional interface ________ in package java.util.function contains method get that takes no arguments and produces a value of type T. Often used to create a collection object in which a stream operation's results are placed.

The basic generic functional interface ________ in package java.util.function contains method test that takes a T argument and returns a boolean. Tests whether the T argument satisfies a condition.

An ________ (package java.util.stream) is a specialized stream for manipulating int values.

Which of the following statements is false?

Terminal Stream operation ________ performs processing on every element in a stream (e.g., display each element).

Intermediate operations are________; they aren't performed until a terminal operation is invoked. This allows library developers to optimize stream-processing performance.

________ is a constructor reference. It creates a lambda that invokes the no-argument constructor of the specified class to create and initialize a new object of that class.

Which statement in the following sequence of statements about sorting objects by two fields is false?

Functional interface BiConsumer's accept method has two parameters. For Maps, the first represents the ________ and the second the corresponding ________.

You can declare that an interface is a functional interface by preceding it with the @FunctionalInterface annotation. The compiler will then ensure that the interface contains ________; otherwise, it'll generate a compilation error.

A lambda expression represents a(n) ________ method-a shorthand notation for implementing a functional interface.

Which of the following statements is false?

Map method entrySet returns a Set of Map.Entry objects containing the Map's ________.

The type of a lambda is the type of the ________ that the lambda implements.

What is the meaning of ( ) in the following lambda? () -> System.out.println("Welcome to lambdas!")

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

Generic Collections

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

GUI

Concurrency

Accessing Databases With JDBC

JavaFX

Filters

Functional interface BiConsumer's accept method has two parameters. For Maps, the first represents the and the second the corresponding .