通常程序員初始化Mapjava
Map<String, Object> map = new HashMap<>(); map.put("key", 2);
二般程序員初始化Map程序員
Map<String, Object> map = new HashMap<>(){{ put("key", 2); }};
懶惰的程序員code
Map<String, Object> map = Collections.singletonMap("key", 2);