How to Iterate Map

常用iterate 方法

 Map<Integer, String> m = new HashMap<Integer, String>();
 for(Map.Entry<Integer, String> entry : m.entrySet()){
     System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue());
 }

 Iterator<Map.Entry<Integer, String>> iterator = m.entrySet().iterator();
 while(iterator.hasNext()){
     Map.Entry entry = iterator.next();
     System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue());
 }

 for(Character key : hm.keySet()){
     System.out.println("Key: " + key + " Value: " + hm.get(key));
 }