HashMap interview questions and ConcurrentHashMap interview questions. Learn questions like how hashmap works, rehashing in concurrenthashmap and more. In “How HashMap works in Java“, we learned the internals of HashMap or ConcurrentHashMap class and how they fit into the whole concept. But ...
2. Is Java HashMap ordered / sorted? Java HashMap does not keep theorderof inserted objects. This means that when you iterate over a map the objects are in a random order. But you can access values in a map by the keys. We’ll take a look at this a bit later under examples. ...
There are many ways to compareHashMaps in Java. We can compare them using theequals()method. The default implementation compares each value. If we change the inner Map’s contents, the equality check fails. If the inner objects are all new instances every time in the case of user-defined...
How HashMap works in Java or sometime how get method work in HashMap is common interview questions now days. Almost everybody who worked in Java knows what hashMap is, where to use hashMap or difference between hashtable and HashMap then why this interview question becomes so special? Beca...
We used Hashmap in both above examples but those are pretty simple use cases of Hashmap.HashMap is a non-synchronizedcollection class. Do you have any of below questions? What’s the difference between ConcurrentHashMap and Collections.synchronizedMap(Map)?
In this post, I will try to cover some relatedinterview questionsusually occur next in chain: Topics covered in this post: How you will design a good key for HashMap? Difference between HashMap and ConcurrentHashMap? Difference between HashMap and Collections.synchronizedMap(HashMap)?
[1]Double Brace Initialization In Java! http://viralpatel.net/blogs/double-brace-initialization-in-java/ [2]Double Brace Initialization Idiom and its Drawbacks http://java.dzone.com/articles/double-brace-initialization [3]Hidden Features of Java http://stackoverflow.com/questions/15496/hidden...
Race condition exists while resizing hashmap in Java. If two threads, at the same time, find that Hashmap needs resizing, they both try resizing the hashMap. In the process of resizing of hashmap, the element in bucket(which is stored in linked list) get reversed in order during the mi...
In this quick tutorial, we’ve seen various techniques to copy aHashMapin Java, along with the concept of shallow and deep copy forHashMaps. Also, we explored some of the external libraries that are quite handy for creating shallow and deep copies. ...
当然,这个数学计算方法,并不是在Java的官方文档中体现的,我们也无从考察到底有没有这层考虑,就像我们根本不知道鲁迅写文章时候怎么想的一样,只能推测。这个推测来源于Stack Overflow(https://stackoverflow.com/questions/10901752/what-is-the-significance-of-load-factor-in-hashmap) 0.75的必然因素 理论上我们认为...