The java.util.PriorityQueue.offer() method is used to insert a particular element into the Priority Queue. It acts similar to the add() method of Priority Queue.
Syntax:
Priority_Queue.offer(Object element)
Parameters: The parameter element is of the type PriorityQueue and refers to the element to be inserted into the Queue.
Return Value: The method returns True if the value is successfully inserted into the queue.
Exceptions: The method can throw two types of exceptions:
- NullPointerException: If the element to be inserted is NULL.
- ClassCastException: If an element to be inserted is of a different type that cannot be compared to the existing elements of the Queue.
Below programs illustrate the java.util.PriorityQueue.offer() method
Program 1:
// Java code to illustrate offer() import java.util.*;
public class PriorityQueueDemo {
public static void main(String args[])
{
// Creating an empty PriorityQueue
PriorityQueue<String> queue = new PriorityQueue<String>();
// Use add() method to add elements into the Queue
queue.add( "Welcome" );
queue.add( "To" );
queue.add( "Geeks" );
queue.add( "4" );
queue.add( "Geeks" );
// Displaying the PriorityQueue
System.out.println( "Initial PriorityQueue: " + queue);
// Inserting using offer()
queue.offer( "The" );
queue.offer( "Priority" );
queue.offer( "Class" );
// Displaying th final Queue
System.out.println( "Priority queue after Insertion: " + queue);
}
} |
Output:
Initial PriorityQueue: [4, Geeks, To, Welcome, Geeks] Priority queue after Insertion: [4, Class, Priority, Geeks, Geeks, To, The, Welcome]
Program 2:
// Java code to illustrate offer() import java.util.*;
public class PriorityQueueDemo {
public static void main(String args[])
{
// Creating an empty PriorityQueue
PriorityQueue<Integer> queue = new PriorityQueue<Integer>();
// Use add() method to add elements into the Queue
queue.add( 10 );
queue.add( 15 );
queue.add( 30 );
queue.add( 20 );
queue.add( 5 );
// Displaying the PriorityQueue
System.out.println( "Initial PriorityQueue: " + queue);
// Inserting using offer()
queue.offer( 100 );
queue.offer( 120 );
queue.offer( 150 );
// Displaying th final Queue
System.out.println( "Priority queue after Insertion: " + queue);
}
} |
Output:
Initial PriorityQueue: [5, 10, 30, 20, 15] Priority queue after Insertion: [5, 10, 30, 20, 15, 100, 120, 150]