Java Interview Guide : 200+ Interview Questions and Answers - Queue interfaces and implementations - Deque and BlockingQ

The video tutorial provides an overview of different types of queues in programming, including the basic queue, double-ended queue, and blocking queue. It explains their operations, such as adding, removing, polling, and peeking elements. The tutorial also covers specific implementations like priority queue, array dequeue, and linked blocking queue, highlighting their characteristics and use cases. The focus is on understanding the interfaces and methods associated with each type of queue, as well as their practical applications in programming.

What is the main difference between the 'remove' and 'poll' methods in a Queue?

• Both methods return null if the queue is empty.

• Remove returns null if the queue is empty, while poll throws an exception.

• Both methods throw an exception if the queue is empty.

• Remove throws an exception if the queue is empty, while poll returns null.

What is a key feature of a Deque?

• It allows elements to be removed only from the front.

• It does not support element removal.

• It allows elements to be added only at the end.

• It allows elements to be added and removed from both ends.

In what scenario would you use a BlockingQueue?

• When you need to add elements at both ends of the queue.

• When you want to wait for the queue to become non-empty before performing operations.

• When you need to process elements in a specific order.

• When you want to avoid exceptions during element removal.

How does the 'offer' method in a BlockingQueue differ from the 'add' method?

• Both methods return false on failure.

• Both methods throw an exception on failure.

• Offer returns false on failure, while add throws an exception.

• Offer throws an exception on failure, while add returns false.

What is the purpose of specifying a wait time in BlockingQueue operations?

• To wait indefinitely for an element to become available.

• To specify a maximum time to wait for an element to become available.

• To ensure immediate insertion of elements.

• To avoid waiting for any time.

Which queue implementation sorts elements in their natural order?

• ArrayDeque

• PriorityQueue

• LinkedBlockingQueue

• ArrayBlockingQueue

What is a characteristic of the LinkedBlockingQueue?

• It uses an array as its underlying data structure.

• It has less predictable performance in highly concurrent applications.

• It is always faster than ArrayBlockingQueue.

• It does not support blocking operations.