2017-08-21 21 views

回答

0

所有被引用。您可以直接導航到該對象並對其進行調用。例如 -

Map<String, Map<String, String>> student = new HashMap<>(); 
student.put("studentObject1", new HashMap<>());//initialize child object once. 
student.get("studentObject1").put("name", "Aarti");//get reference of child object and put key value in it.