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Java: Retrieve the first element of the priority queue


8. Peek First PriorityQueue Element

Write a Java program to retrieve the first element of the priority queue.

Sample Solution:-

Java Code:

import java.util.PriorityQueue;
  public class Example8 {
  public static void main(String[] args) {

   // Create Priority Queue
      PriorityQueue<Integer> pq1 = new PriorityQueue<Integer>();  
      PriorityQueue<Integer> pq2 = new PriorityQueue<Integer>();  
        
   // Add numbers in the Queue
   pq1.add(10);
   pq1.add(22);
   pq1.add(36);
   pq1.add(25);
   pq1.add(16);
   pq1.add(70);
   pq1.add(82);
   pq1.add(89);
   pq1.add(14);
   System.out.println("Original Priority Queue: "+pq1);
   System.out.println("The first element of the Queue: "+pq1.peek());
   }    
}

Sample Output:

Original Priority Queue: [10, 14, 36, 16, 22, 70, 82, 89, 25]          
The first element of the Queue: 10

For more Practice: Solve these Related Problems:

  • Write a Java program to retrieve the head of a PriorityQueue using peek() and print it.
  • Write a Java program to create a PriorityQueue with a custom comparator and then retrieve the first element to verify the ordering.
  • Write a Java program to use a lambda expression to fetch the first element from a PriorityQueue and display it.
  • Write a Java program to insert elements into a PriorityQueue and then retrieve the head element after each insertion to observe changes.

Go to:


PREV : Compare PriorityQueues.
NEXT : Poll First PriorityQueue Element.

Java Code Editor:

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