Java中遍历Map集合的几种方式

Java中遍历Map集合的几种方式

 Map<Integer,Object> hashMap = new HashMap<Integer,Object>();
       hashMap.put(1,"张三");
       hashMap.put(3,"李四");
       hashMap.put(5,"王五");
       hashMap.put(2,"赵六");
         //迭代器形式
        Iterator<Map.Entry<Integer, Object>> iterator = hashMap.entrySet().iterator();
        while(iterator.hasNext()) {
            Map.Entry<Integer, Object> next = iterator.next();

        }
        //ForEach EntrySet
        for (Map.Entry<Integer, Object> entry : hashMap.entrySet()) {
            System.out.println("Key的值为：" + entry.getKey());
            System.out.println("value的值为：" + entry.getValue());
        }

        // entrySet形式
        for (Map.Entry<Integer, Object> objectEntry : hashMap.entrySet()) {
            System.out.println(objectEntry.getKey() + "=" + objectEntry.getValue());
        }

        //keyset形式
        for(Integer i:hashMap.keySet()){
            System.out.println("当前的key是："+i+"当前的value是："+hashMap.get(i));
        }

      //Lambda形式
       hashMap.forEach((key,value)->{
           System.out.println(key+"==="+value);
       });

     //stream形式
        hashMap.entrySet().stream().forEach((entry) -> {
            System.out.println("Key的值为：" + entry.getKey());
            System.out.println("value的值为：" + entry.getValue());
        });