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Java Lambda Expressions and Streams
Question 1
Which of the following is true about lambda expressions in Java?
- A
Lambda expressions can be used to define a method.
- B
Lambda expressions are instances of functional interfaces.
- C
Lambda expressions cannot access instance variables.
- D
Lambda expressions are not supported in Java 8.
Question 2
What is the correct syntax for a lambda expression in Java?
- A
(parameter) -> {body}
- B
parameter => body
- C
parameter -> {body}
- D
{parameter} -> body
Question 3
What will the following lambda expression do? x -> x * 2
- A
Doubles the value of x
- B
Prints the value of x
- C
Doubles the value of x and prints it
- D
Nothing
Question 4
What does the following code snippet represent? () -> { return 42; }
- A
A method reference
- B
A functional interface
- C
A lambda expression
- D
An anonymous class
Question 5
Which of the following functional interfaces can be used with lambda expressions in Java?
- A
Runnable
- B
Callable
- C
Comparator
- D
All of the above
Question 6
Which of the following lambda expressions is correct for a function that takes two integers and returns their sum?
- A
(a, b) -> a + b
- B
a, b -> {return a + b;}
- C
(a, b) { return a + b }
- D
(a, b) -> a * b
Question 7
Which of these statements correctly describes the Stream API in Java 8?
- A
Streams are used to process collections of objects sequentially or in parallel.
- B
Streams allow modifying the original data source.
- C
Streams are primarily used to create new collections.
- D
Streams only allow sequential processing.
Question 8
Which of the following is an intermediate operation in the Stream API?
- A
collect()
- B
map()
- C
forEach()
- D
reduce()
Question 9
Which of the following is a terminal operation in the Stream API?
- A
map()
- B
filter()
- C
reduce()
- D
flatMap()
Question 10
How can a stream be parallelized in Java?
- A
By using stream.parallel()
- B
By using stream.parallelize()
- C
By using parallelStream()
- D
By using stream.split()
There are 13 questions to complete.
