What will happen when you try to create an array of generics? List[] array = new List[10];

The correct answer is A: Compilation error. You cannot create arrays of generic types because of type erasure. The compiler prevents this with a compilation error.

What is the key difference between Callable and Runnable?

The correct answer is A: Callable can return a value and throw checked exceptions; Runnable cannot. Callable can return a value of type V and throw checked exceptions. Runnable has void run() method and cannot throw checked exceptions.

Consider the following code. What will be printed? String s = "Java"; s = s.concat(" Programming"); System.out.println(s.length());

The correct answer is C: 17. "Java" has 4 characters. After concatenation with " Programming" (12 characters including space), the total length is 4 + 13 = 17 characters.

In a CSV file processing application, why is BufferedReader preferred over FileReader for reading large files?

The correct answer is B: BufferedReader reduces I/O operations by reading data in chunks. BufferedReader buffers input, reducing system calls and I/O overhead, improving performance significantly.

Which class would you use to read and write at arbitrary positions in a file?

The correct answer is C: RandomAccessFile. RandomAccessFile allows reading and writing at arbitrary positions using seek() method, useful for direct access to file contents.

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Java Programming
Lambda Expressions

Java OOP, collections, multithreading

32 Q 10 Topics Take Mock Test

Difficulty: All Easy Medium Hard 31–32 of 32

Topics in Java Programming

All Basics & Syntax 100 OOP in Java 100 Collections Framework 100 Multithreading 100 Exception Handling 100 I/O Streams 100 JDBC 100 Generics 100 Lambda Expressions 100 Spring Framework Basics 58

Q.31 Easy Lambda Expressions

Which of the following is a valid lambda expression syntax in Java?

A (int x, int y) -> x + y

B (x, y) => x + y

C [x, y] -> x + y

D (x, y) : x + y

Correct Answer: A. (int x, int y) -> x + y

EXPLANATION

Valid Java lambda syntax uses arrow operator (->). Parameters can be typed or untyped, and the expression or block follows the arrow.

Test

Q.32 Easy Lambda Expressions

What is the primary purpose of lambda expressions introduced in Java 8?

A To provide a concise syntax for implementing functional interfaces

B To replace all anonymous inner classes

C To improve memory management

D To simplify exception handling

Correct Answer: A. To provide a concise syntax for implementing functional interfaces

EXPLANATION

Lambda expressions provide a concise way to implement single abstract method (functional interfaces) without verbose anonymous class syntax.

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Java Programming Lambda Expressions

Java Programming
Lambda Expressions