1 package test_18_1;
 2 
 3 import java.util.ArrayList;
 4 import java.util.Collection;
 5 import java.util.HashSet;
 6 import java.util.Iterator;
 7 import java.util.LinkedList;
 8 import java.util.TreeSet;
 9 
10 public class IteratorTest {
11 
12     static Collection fill(Collection<String> collection) {
13         
14         for (int i = 0; i < 10; i++) {
15             collection.add("" + i);
16         }
17         
18         return collection;
19     }
20     
21     static void iterator(Iterator<String> it) {
22         while (it.hasNext()) {
23             String str = it.next();
24             System.out.print(str.toString() + "  ");
25         }
26         System.out.println();
27     }
28     
29     public static void main(String[] args) {
30         ArrayList<String> strAL = new ArrayList<String>();
31         fill(strAL);
32         iterator(strAL.iterator());
33         
34         LinkedList<String> strLL = new LinkedList<String>();
35         fill(strLL);
36         iterator(strLL.iterator());
37         
38         HashSet<String> strHS = new HashSet<String>();
39         fill(strHS);
40         iterator(strHS.iterator());
41         
42         TreeSet<String> strTS = new TreeSet<String>();
43         fill(strTS);
44         iterator(strTS.iterator());
45         
46     }
47 }