遍历map的五种方法介绍

        Iterator<Map.Entry<Integer,String>> iterator=map.entrySet().iterator();
        while(iterator.hasNext()){
            Map.Entry<Integer,String> entry=iterator1.next();
            System.out.println(entry.getKey());
            System.out.println(entry.getValue());
        }

        Iterator<Integer> iterator=map.keySet().iterator();
        while (iterator.hasNext()){
            Integer key=iterator.next();
            System.out.println(key);
            System.out.println(map.get(key));
        }

        for(Map.Entry<Integer,String> entry:map.entrySet()){
            System.out.println(entry.getKey());
            System.out.println(entry.getValue());
        };

        map.forEach((key,value)->{
            System.out.println(key);
            System.out.println(value);
        });

        map.entrySet().stream().forEach((Map.Entry<Integer, String> entry) -> {
            System.out.println(entry.getKey());
            System.out.println(entry.getValue());
        });