Note: If you override equals(), you must override hashb() as well. The equals() method compares two objects for equality and returns true if they are equal. The equals() method provided in the Object class uses the identity operator (==) to determine whether two objects are equal. For primitive data types, this gives the correct result. For objects, however, it does not. The equals() method provided by Object tests whether the object references are equal—that is, if the objects compared are the exact same object. To test whether two objects are equal in the sense of equivalency (containing the same information), you must override the equals() method. Here is an example of a Book class that overrides equals() : Consider this b that tests two instances of the Book class for equality: