hashCode

[Bobby Sh]

On the Dan Chisholm web site for Certified Java Programmer Mock Exam I got the following question:
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 given is
a. false

Please carify.My opinion is that the hashCode should always return the same integer and answer should be true. :roll:

[Praveen Mathur]

Quotes from Java API ()
"
The general contract of hashCode is:
(1)
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.
(2)
If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
(3)
It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables.
"
I think , It should be clear to you now.

[Bobby Sh]

Thanks Praveen .....