PriorityBlockingQueue clear() method in Java
The clear() method of PriorityBlockingQueue removes all the elements from this queue. Therefore this method can be applied when it is required to clear the PriorityBlockingQueue.
Syntax:
public void clear()
Parameter:
This method takes no parameters.
Returns:
This method returns nothing.
Exception:
This method does not throw any Exception.
Below program illustrate removing all the elements from PriorityBlockingQueue using clear() method.
Example 1:
// Java Program to Demonstrate clear() method// of PriorityBlockingQueue.  import java.util.concurrent.PriorityBlockingQueue;  public class GFG {      public static void main(String[] args)    {        // define capacity of PriorityBlockingQueue        int capacity = 15;          // create object of PriorityBlockingQueue        PriorityBlockingQueue<Integer> PrioBlockingQueue            = new PriorityBlockingQueue<Integer>(capacity);          // add numbers        PrioBlockingQueue.add(78758575);        PrioBlockingQueue.add(63447688);        PrioBlockingQueue.add(56434788);          // print queue after add operation        System.out.println("After Adding Numbers:");        System.out.println("PriorityBlockingQueue:"                           + PrioBlockingQueue);          // remove all the elements using clear() method        PrioBlockingQueue.clear();          // print queue after clear operation        System.out.println("\nAfter clear operation:");        System.out.println("PriorityBlockingQueue:"                           + PrioBlockingQueue);    }} |
Output:
After Adding Numbers: PriorityBlockingQueue:[56434788, 78758575, 63447688] After clear operation: PriorityBlockingQueue:[]
Example 2: To illustrate clear method on a PriorityBlockingQueue which contains a list of names.
// Java Program to Demonstrate clear() method// of PriorityBlockingQueue.  import java.util.concurrent.PriorityBlockingQueue;  public class GFG {      public static void main(String[] args)    {        // define capacity of PriorityBlockingQueue        int capacity = 15;          // create object of PriorityBlockingQueue        PriorityBlockingQueue<String> PrioBlockingQueue            = new PriorityBlockingQueue<String>(capacity);          // add some names        PrioBlockingQueue.add("Tandrima");        PrioBlockingQueue.add("Argha");        PrioBlockingQueue.add("Arka");          // print queue after add operation        System.out.println("List of Names:");        System.out.println("PriorityBlockingQueue: "                           + PrioBlockingQueue);          // remove all the elements using clear() method        PrioBlockingQueue.clear();          // print queue after clear operation        System.out.println("\nAfter clearing List of names:");        System.out.println("PriorityBlockingQueue:"                           + PrioBlockingQueue);    }} |
Output:
List of Names: PriorityBlockingQueue: [Argha, Tandrima, Arka] After clearing List of names: PriorityBlockingQueue:[]
Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/PriorityBlockingQueue.html#clear–
