What is the output of the following program:import java.util.*;class Queue1 { public static void main(String args[]) { PriorityQueue<String> queue = new PriorityQueue<String>(); System.out.println(queue.element()); }}Select one:a. None of the choicesb. Program will throw an exceptionc. No outputd. n
Question
What is the output of the following program:import java.util.*;class Queue1 { public static void main(String args[]) { PriorityQueue<String> queue = new PriorityQueue<String>(); System.out.println(queue.element()); }}Select one:a. None of the choicesb. Program will throw an exceptionc. No outputd. n
Solution
The correct answer is b. Program will throw an exception.
Here's why:
The PriorityQueue class in Java does not allow null values and we are trying to access an element from an empty queue. The element() method retrieves, but does not remove, the head of this queue. This method differs from peek only in that it throws an exception if this queue is empty. So, when we try to print the element of an empty queue, it
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