Confusion about size and capacity of Stack class

Question

import java.util.*;
public class StackDemo {
     static void s_pop(Stack<Integer> s)
          System.out.print("Pop elements of Stack: ");
          try
               for(int i=0;i<s.size();i++)
                    System.out.print(s.pop()+" ");
          }catch(EmptyStackException e)
               System.out.println("Empty Stack");
     public static void main(String[] args) {
          Stack<Integer> s=new Stack<Integer>();
          System.out.println("Size of Stack s: "+s.size());
          System.out.println("Capacity of Stack s: "+s.capacity());
          s.push(10);
          s.push(29);
          s.push(76);
          s.push(-7);
          System.out.println("Now the size of Stack s: "+s.size());
          System.out.println("Now the capacity of Stack s: "+s.capacity());
          System.out.print("Elements of Stack: ");
          for(int i:s)
               System.out.print(i+" ");
          System.out.println();
          s.push(32);
          s.push(46);
          System.out.println("Now the Size of Stack s: "+s.size());
          System.out.println("Now the capacity of Stack s: "+s.capacity());
          System.out.print("Elements of Stack: ");
          for(int i:s)
               System.out.print(i+" ");
          System.out.println();
          s_pop(s);
} The outputs:
Size of Stack s: 0
Capacity of Stack s: 10
Now the size of Stack s: 4
Now the capacity of Stack s: 10
Elements of Stack: 10 29 76 -7
Now the Size of Stack s: 6
Now the capacity of Stack s: 10
Elements of Stack: 10 29 76 -7 32 46
Pop elements of Stack: 46 32 -7 // where are the other elements of Stack
import java.util.*;
public class StackDemo {
     static void s_pop(Stack<Integer> s)
          System.out.print("Pop elements of Stack: ");
          try
               for(int i=0;i<s.capacity();i++)
                    System.out.print(s.pop()+" ");
          }catch(EmptyStackException e)
               System.out.println("Empty Stack");
     public static void main(String[] args) {
          Stack<Integer> s=new Stack<Integer>();
          System.out.println("Size of Stack s: "+s.size());
          System.out.println("Capacity of Stack s: "+s.capacity());
          s.push(10);
          s.push(29);
          s.push(76);
          s.push(-7);
          System.out.println("Now the size of Stack s: "+s.size());
          System.out.println("Now the capacity of Stack s: "+s.capacity());
          System.out.print("Elements of Stack: ");
          for(int i:s)
               System.out.print(i+" ");
          System.out.println();
          s.push(32);
          s.push(46);
          System.out.println("Now the Size of Stack s: "+s.size());
          System.out.println("Now the capacity of Stack s: "+s.capacity());
          System.out.print("Elements of Stack: ");
          for(int i:s)
               System.out.print(i+" ");
          System.out.println();
          s_pop(s);
The outputs:
Size of Stack s: 0
Capacity of Stack s: 10
Now the size of Stack s: 4
Now the capacity of Stack s: 10
Elements of Stack: 10 29 76 -7
Now the Size of Stack s: 6
Now the capacity of Stack s: 10
Elements of Stack: 10 29 76 -7 32 46
Pop elements of Stack: 46 32 -7 76 29 10 Empty Stack
When i use s.size() in the first program then only first 3 elements are poped.But when i use s.capacity() in the second program then all of the elements are poped.But the size of the stack is 6 in both program.Then why all of the elements are not poped when I use size method of Stack????

Answer 1

> for(int i=0;i<s.size();i++)
     System.out.print(s.pop()+" ");
}Realize that s.size() is computed everytime the loop body is entered.
That size changes after the loop body (the 'pop') has been executed.
Better do this:for (int i= 0, n= s.size(); i < n; i++)
   System.out.print(s.pop()+" ");kind regards,
Jos