Dans exam

[Pradeep bhatt]

A class C has legal implementations of the equals and hashCode methods. On Monday, an instance of the class is created and the hashCode method is invoked. On Tuesday the program is loaded again and an instance of class C is created containing the same data that was loaded on Monday. If the hashCode method is invoked after restarting the program on Tuesday then the hashCode method must return the same integer value that was returned on Monday.
a. false
b. true
The answer is given as (a) but I think it should be b.

[Alfred Kemety]

Nope hashCode() doesn't need to return the same int value so that it is properly implemented.
API says:

The general contract of hashCode is:
Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.

It's more than once during AN execution, so even if it's still Monday and you reload the application - close it, then open it again - and it returns a different int value, it can still be implemented correctly and it doesn't violate the contract.
HTH