Question

Does anyone use hashCode() anywhere?

Can anyone give me an example of the exact use of hashcode and in which cases we need to implement it?
Any specific area where HashCode is being used?

Answer 1

Does hascode use any where?

The hashCode method is used internally by for instance HashSet or HashMap etc.

Do any one give me example what is exact use of hascode …

It is used to for instance allow an algorithm to quickly discover if two objects are not equal. (Without comparing them using equals.)

…and in which cases we need to implement it?

You should implement it whenever you override equals (which you need to do whenever you need to define two different objects to be equal).

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Further reading

• Best implementation for hashCode method
• Wikipedia: Hash table (I strongly suggest you read this)