The answer is NO . Making keys in any hashing data structure will cause memory leak. If we make the keys mutable then the hashcode() of the key will no more be consistent over time which will cause lookup failure for that object from the data structure.3 Ağu 2019
Read moreCan we create HashMap key immutable or mutable will be better?
Both hashcode and equals method are used in put and get method of HashMap. You need to make sure you can always get the value object from the map after you put it with the key object. No matter you change the key object or not. But Immutable object is good enough to achieve that .26 Kas 2013
Read moreIs HashMap key immutable?
Make HashMap key object immutable Immutability allows you to get same hash code every time, for a key object . So it actually solves most of the problems in one go. Also, this class must honor the hashCode() and equals() methods contract.25 Oca 2022
Read moreHow do you make a HashMap immutable?
We used to use the unmodifiableMap() method of Collections class to create unmodifiable(immutable) Map. Map<String,String> map = new HashMap<String, String>(); Map<String,String> immutableMap = Collections. unmodifiableMap(map);
Read moreHow do you make an employee object a key in HashMap?
If you want to make a mutable object as key in hashmap, then you have to make sure that state change for key object does not change the hash code of object. This can be done by overriding the hashCode() method . But, you must make sure you are honoring the contract with equals() also.
Read moreCan we use employee class as key in HashMap?
Answer to your question is yes, objects of custom classes can be used as a key in a HashMap.
Read moreHow does a HashMap store items in memory?
A HashMap stores data into multiple singly linked lists of entries (also called buckets or bins) . … All the keys with the same hash value are put in the same linked list (bucket). Keys with different hash values can end-up in the same bucket.
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