map普通遍历+java8的Lambda表达式

一：普通方式、

1、keySet()：

        Map<String, Object> map = new HashMap<>();
        map.put("name", "张三");
        map.put("age", 20);
        for (String key : map.keySet()) {
            String value = map.get(key).toString();
            System.out.println(key);
            System.out.println(value);
        }

2、entrySet()：

        Map<String, Object> map = new HashMap<>();
        map.put("name", "张三");
        map.put("age", 20);
        Set<Map.Entry<String, Object>> entries = map.entrySet();
        for (Map.Entry<String, Object> entry : entries){
            System.out.println(entry.getKey());
            System.out.println(entry.getValue());
        }

二：Lambda遍历、

1、entrySet()：

 Map<String, Object> map = new HashMap<>();
        map.put("name", "张三");
        map.put("age", 20);
        Set<Map.Entry<String, Object>> entries = map.entrySet();
        entries.forEach(entry -> System.out.println(entry.getKey() + "=" + entry.getValue()));

2、forEach()：

Map<String, Object> map = new HashMap<>();
        map.put("name", "张三");
        map.put("age", 20);
        map.forEach((key, value) -> System.out.println(key + "=" + value));