Question

The remove() method in the Queue interface ________. Group of answer choices retrieves, but does not remove, the head of this queue, returning null if this queue is empty retrieves and removes the head of this queue, or null if this queue is empty retrieves, but does not remove, the head of this queue, throwing an exception if this queue is empty retrieves and removes the head of this queue and throws an exception if this queue is empty

Answer 1

Question:

The remove() method in the Queue interface ________.

A. retrieves, but does not remove, the head of this queue, returning null if this queue is empty

B. retrieves and removes the head of this queue, or null if this queue is empty

 

C. retrieves, but does not remove, the head of this queue, throwing an exception if this queue is empty

D. retrieves and removes the head of this queue and throws an exception if this queue is empty

Answer:

D. retrieves and removes the head of this queue and throws an exception if this queue is empty

Explanation:

In Java, the Queue interface is found in the java.util package and inherits from the Collection interface. It is used to store elements which are processed in the order in which they are inserted. This means that the first element will be processed first.

The Queue interface has many methods. Some of them are;

i. add(): allows elements to be added to the queue.

ii. remove(): retrieves and removes elements from the head of the queue. The head of the queue points to the first element of the queue. If the queue is empty, the remove() method throws an exception called the NoSuchElementException

iii. poll(): retrieves and removes the element at the head of the queue. Unlike the remove() method, if the queue is empty, a null is returned.

iv. peek(): retrieves but does not remove the element at the head of the queue. Just like the poll() method, a null is returned if the queue is empty.