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. No outputb. None of the choicesc. Program will throw an exceptiond. null
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. No outputb. None of the choicesc. Program will throw an exceptiond. null
Solution
The correct answer is c. 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 will throw NoSuchElementException.
Similar Questions
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>(); queue.add("Amit"); queue.add("Vijay"); queue.add("Karan"); System.out.println("Printing queue elements:"); Iterator itr = queue.iterator(); while (itr.hasNext()) { System.out.println(itr.next()); } queue.remove(); System.out.println("Printing queue elements:"); Iterator<String> itr2 = queue.iterator(); while (itr2.hasNext()) { System.out.println(itr2.next()); } }}
import java.util.*;class Queue1 { public static void main(String args[]) { PriorityQueue<String> queue = new PriorityQueue<String>(); System.out.println(queue.element()); }}
What is the output of the following code?import java.util.*;public class Main { public static void main(String[] args) { Queue queue = new LinkedList<>(); queue.add(1); queue.add(2); queue.add(3); System.out.println(queue.poll()); System.out.println(queue.poll()); System.out.println(queue.poll()); }}a)3 1 2b)3 2 1c)1 3 2d)1 2 3
import java.util.*;class Queue1 { public static void main(String args[]) { PriorityQueue<String> queue = new PriorityQueue<String>(); queue.add("Amit"); queue.add("Vijay"); queue.add("Karan"); System.out.println("Printing queue elements:"); Iterator itr = queue.iterator(); while (itr.hasNext()) { System.out.println(itr.next()); } queue.remove(); System.out.println("Printing queue elements:"); Iterator<String> itr2 = queue.iterator(); while (itr2.hasNext()) { System.out.println(itr2.next()); } }}
What will be the output of the following Java program?class mainclass { public static void main(String args[]) { boolean ct1 = true; boolean ct2 = false; if (ct1) System.out.println(ct1); else System.out.println(ct2); } }Options10truefalse
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.