Can we override hashCode method in Java?

if a class overrides equals, it must override hashCode . when they are both overridden, equals and hashCode must use the same set of fields . if two objects are equal, then their hashCode values must be equal as well. if the object is immutable, then hashCode is a candidate for caching and lazy initialization.31 Ara 2021

If you don’t override hashcode() then the default implementation in Object class will be used by collections . This implementation gives different values for different objects, even if they are equal according to the equals() method.

So all java classes have the hashcode() method by default. We can override these methods in our classes . Hashcode() is a method to return an unique integer which is used for indentifying the bucket where this object will be stored for hashing based collections like HashMap.