// collections/PrintingCollections.java // (c)2017 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://OnJava8.com for more book information. // Collections print themselves automatically import java.util.*; public class PrintingCollections { static Collection fill(Collection collection) { collection.add("rat"); collection.add("cat"); collection.add("dog"); collection.add("dog"); return collection; } static Map fill(Map map) { map.put("rat", "Fuzzy"); map.put("cat", "Rags"); map.put("dog", "Bosco"); map.put("dog", "Spot"); return map; } public static void main(String[] args) { System.out.println(fill(new ArrayList<>())); System.out.println(fill(new LinkedList<>())); System.out.println(fill(new HashSet<>())); System.out.println(fill(new TreeSet<>())); System.out.println(fill(new LinkedHashSet<>())); System.out.println(fill(new HashMap<>())); System.out.println(fill(new TreeMap<>())); System.out.println(fill(new LinkedHashMap<>())); } } /* Output: [rat, cat, dog, dog] [rat, cat, dog, dog] [rat, cat, dog] [cat, dog, rat] [rat, cat, dog] {rat=Fuzzy, cat=Rags, dog=Spot} {cat=Rags, dog=Spot, rat=Fuzzy} {rat=Fuzzy, cat=Rags, dog=Spot} */