1、Map的特性即「键-值」(Key-Value)匹配java.util.HashMap实作了Map界面,HashMap在内部实作使用哈希(Hash),很快的时间内可以寻得「键-值」匹配.2. Map<String, String> map = new HashMap<String, String>(); String key1 = "caterpillar"; String key2 = "justin"; map.put(key1, "caterpillar的讯息"); map.put(key2, "justin的讯息"); System.out.println(map.get(key1)); System.out.println(map.get(key2));
2、可以使用values()方法返回一个实作Collection的对象,当中包括所有的「值」对象. Map<String, String> map = new HashMap<String, String>(); map.put("justin", "justin的讯息"); map.put("momor", "momor的讯息"); map.put("caterpillar", "caterpillar的讯息"); Collection collection = map.values(); Iterator iterator = collection.iterator(); while(iterator.hasNext()) { System.out.println(iterator.next()); } System.out.println();
3、 Map<String, String> map = new LinkedHashMap<String, String>(); map.put("justin", "justin的讯息"); map.put("momor", "momor的讯息"); map.put("caterpillar", "caterpillar的讯息"); for(String value : map.values()) { System.out.println(value); }