Java Lambda & Streams Quiz

Last updated over 2 years ago

15 questions

Single/Multiple choise:

1

Untitled Section

What is the syntax for a lambda expression in Java?

{params} -> expression

(params) -> expression

(params) => expression

{params} => expression

Which of the following functional interfaces represents a function that takes an argument and returns a result?

Consumer

Supplier

Function

BiConsumer

What is the purpose of the anyMatch() method in Java streams?

It returns true if all elements of the stream match the given predicate.

It returns true if any element of the stream matches the given predicate.

It returns true if none of the elements of the stream match the given predicate.

It returns true if the stream is empty.

Which of the following terminal operations does not return a value in Java streams?

forEach()

collect()

map()

reduce()

What does the sorted() method do in Java streams?

It shuffles the elements of the stream randomly.

It sorts the elements of the stream in reverse order.

It sorts the elements of the stream in natural order.

It doesn't have any effect on the order of elements in the stream.

What is the output of the following Java stream operation?
List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
int result = numbers.stream()
.filter(x -> x % 2 == 0)
.mapToInt(x -> x)
.sum();
System.out.println(result);

6

9

10

15

What does the collect() terminal operation do in Java streams?

Transforms each element in the stream

Reduces the elements of the stream to a single value

Collects the elements of the stream into a collection

Checks if any element matches a given condition

Which functional interface represents a function that takes an argument and returns a boolean result?

Consumer

Predicate

Supplier

Function

Which terminal operation is used to find the maximum element in a stream?

max()

findMax()

maximum()

findFirst()

Terminal short-circuiting operations are:

Which of the following terminal operations in Java streams can produce results of type Optional?

findFirst()

findAny()

max(Comparator)

min(Comparator)

Which of the following Java stream intermediate operations are stateful?

map()

sorted()

filter()

distinct()

Which of the following Java stream terminal operations are stateless?

What is the output of the following Java stream operation?
List<String> words = Arrays.asList("apple", "orange", "grape", "melon", "banana",);
String result = words.stream()
.filter(s -> s.length() > 5)
.findFirst()
.orElse("No word found");

"No word found"

"apple"

"orange"

"banana"

What is the value of result after executing this code?
Function<Integer, Integer> addTwo = x -> x + 2;
int result = addTwo.apply(5);

5

7

10

Compilation error

What is the syntax for a lambda expression in Java?

{params} -> expression

(params) -> expression

(params) => expression

{params} => expression

Which of the following functional interfaces represents a function that takes an argument and returns a result?

Consumer

Supplier

Function

BiConsumer

What is the purpose of the anyMatch() method in Java streams?

It returns true if all elements of the stream match the given predicate.

It returns true if any element of the stream matches the given predicate.

It returns true if none of the elements of the stream match the given predicate.

It returns true if the stream is empty.

Which of the following terminal operations does not return a value in Java streams?

forEach()

collect()

map()

reduce()

What does the sorted() method do in Java streams?

It shuffles the elements of the stream randomly.

It sorts the elements of the stream in reverse order.

It sorts the elements of the stream in natural order.

It doesn't have any effect on the order of elements in the stream.

What is the output of the following Java stream operation?
List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
int result = numbers.stream()
                   .filter(x -> x % 2 == 0)
                   .mapToInt(x -> x)
                   .sum();
System.out.println(result);

6

9

10

15

What does the collect() terminal operation do in Java streams?

Transforms each element in the stream

Reduces the elements of the stream to a single value

Collects the elements of the stream into a collection

Checks if any element matches a given condition

Which functional interface represents a function that takes an argument and returns a boolean result?

Consumer

Predicate

Supplier

Function

Which terminal operation is used to find the maximum element in a stream?

max()

findMax()

maximum()

findFirst()

Terminal short-circuiting operations are:

findAny()

findFirst()

anyMatch(Predicate)

allMatch(Predicate)

noneMatch(Predicate)

Which of the following terminal operations in Java streams can produce results of type Optional?

findFirst()

findAny()

max(Comparator)

min(Comparator)

Which of the following Java stream intermediate operations are stateful?

map()

sorted()

filter()

distinct()

Which of the following Java stream terminal operations are stateless?

map()

filter()

distinct()

sorted()

flatMap()

What is the output of the following Java stream operation?
List<String> words = Arrays.asList("apple",  "orange", "grape", "melon", "banana",);
String result = words.stream()
                    .filter(s -> s.length() > 5)
                    .findFirst()
                    .orElse("No word found");

"No word found"

"apple"

"orange"

"banana"

What is the value of result after executing this code?
Function<Integer, Integer> addTwo = x -> x + 2; 
int result = addTwo.apply(5);

5

7

10

Compilation error

Java Lambda & Streams Quiz

Java Lambda & Streams Quiz

What is the syntax for a lambda expression in Java?

Which of the following functional interfaces represents a function that takes an argument and returns a result?

What is the purpose of the anyMatch() method in Java streams?

Which of the following terminal operations does not return a value in Java streams?

What does the sorted() method do in Java streams?

What is the output of the following Java stream operation?List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);int result = numbers.stream() .filter(x -> x % 2 == 0) .mapToInt(x -> x) .sum();System.out.println(result);

What does the collect() terminal operation do in Java streams?

Which functional interface represents a function that takes an argument and returns a boolean result?

Which terminal operation is used to find the maximum element in a stream?

Terminal short-circuiting operations are:

Which of the following terminal operations in Java streams can produce results of type Optional?

Which of the following Java stream intermediate operations are stateful?

Which of the following Java stream terminal operations are stateless?

What is the output of the following Java stream operation?List<String> words = Arrays.asList("apple", "orange", "grape", "melon", "banana",);String result = words.stream() .filter(s -> s.length() > 5) .findFirst() .orElse("No word found");

What is the value of result after executing this code?Function<Integer, Integer> addTwo = x -> x + 2; int result = addTwo.apply(5);

What is the output of the following Java stream operation?
List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
int result = numbers.stream()
.filter(x -> x % 2 == 0)
.mapToInt(x -> x)
.sum();
System.out.println(result);

What is the output of the following Java stream operation?
List<String> words = Arrays.asList("apple", "orange", "grape", "melon", "banana",);
String result = words.stream()
.filter(s -> s.length() > 5)
.findFirst()
.orElse("No word found");

What is the value of result after executing this code?
Function<Integer, Integer> addTwo = x -> x + 2;
int result = addTwo.apply(5);