HashMap的遍历方式

1、通过iterator遍历  又分为keySet和entrySet两种

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




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

2、通过加强for循环

for (int key: map.keySet()){
            System.out.println("asdasd"+key);
        }

  for( Map.Entry<Integer,String> entry : map.entrySet()){
            System.out.println(entry.getKey()+"5555555");
        }

3、lambda表达式进行遍历

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

4、通过stream流进行计算

 map.entrySet().stream().forEach((entry)->{
            System.out.println("bianliHashMap.main"+entry.getKey());
        });