险些忘记List传的是引用
差点忘记List传的是引用
List<String> data = new ArrayList<String>();
HashMap<String, List<String>> hashMap = new HashMap<String, List<String>>();
hashMap.put("1", data);
Log.i("test", "Hashmap size now is 1: " + hashMap.size());
List<String> list = hashMap.get("1");
Log.i("test", "List size must be 0: " + list.size());
data.add("8");
data.add("9");
Log.i("test", "List size : " + list.size());
可以先把List放进Map中，再操作List,反正是传引用不是传值！