compare method arguments ?

[aslika bahini]

  
 
import java.util.*;class PQ
{ 
 static class PQsort implements Comparator<Integer>  
 { // inverse sort   
   public int compare(Integer one, Integer two)   
   {        
     return two - one;     
   } 
 }
}
  

PQsort pqs = new PQsort();
Priorityqueue<Ingeger> pq2 = new priorityqueue<Integers>(10,pqs);

Creates a PriorityQueue with the specified initial capacity that
orders its elements according to the specified comparator.

initialCapacity - the initial capacity for this priority queue.
comparator - the comparator used to order this priority queue. If
null then the order depends on the elements'
natural ordering.

the 2nd parameter in the priorityqueue constructor invokes the
compare of method. (which happens behind the scene)
what arguments are passed inside compare of method?
say here public int compare(Integer one, Integer two)
what one and two holds?
can anyone explain

Thanks
samura

[marc weber]

import java.util.*;
 
class PQsort implements Comparator<Integer> {
  public int compare(Integer one, Integer two) {
    System.out.println("  Comparing " + one + " and " + two);
    return two - one; 
  } 
}
 
class Test {
  public static void main(String[] args) {
    PQsort pqs = new PQsort();
    PriorityQueue<Integer> pq2 = new PriorityQueue<Integer>(10, pqs);
    for(int x = 0; x < 10; x++) {
      int thisInt = (int)(Math.random() * 20);
      System.out.println("\nAdding " + thisInt);
      pq2.add(new Integer(thisInt));
      System.out.println("  Queue: " + pq2);
    }
  }
}

This might not completely answer your question, but it should suggest an approach to investigating questions like this.
[ July 02, 2007: Message edited by: marc weber ]

[aslika bahini]

ObjectArrayPriorityQueue(int capacity, Comparator c)
Creates a new empty queue with a given capacity and comparator.

Is the above one is same as this
priorityqueue(int capacity, Comparator c)?

Thanks
samura

[marc weber]

These are entirely different classes:

PriorityQueue is part of Sun's standard Java API.

ObjectArrayPriorityQueue is a third-party class from fastutil. (See the fastutil site for details.)

No third-party classes are covered in the SCJP exam.