File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Programmer Certification (SCJP/OCPJP) and the fly likes A question about equals() method Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of REST with Spring (video course) this week in the Spring forum!
JavaRanch » Java Forums » Certification » Programmer Certification (SCJP/OCPJP)
Bookmark "A question about equals() method" Watch "A question about equals() method" New topic

A question about equals() method

avseq anthoy
Ranch Hand

Joined: Apr 27, 2004
Posts: 106
I see Sun Certified Programmer for Java 2 Study Guide and it says that if you want objects of your class to be used as keys for a hashtable then you must override equals().But why I can put a class defined by myself into HashTable?

why the following sample has overridden equals() and hashcode() but printed "test null" rather than "test test"?

My Way,My Pace
Dan Chisholm
Ranch Hand

Joined: Jul 02, 2002
Posts: 1865
The C in hashCode should be upper case. You have used lower case characters, so you really did not override the hashCode method.

Dan Chisholm<br />SCJP 1.4<br /> <br /><a href="" target="_blank" rel="nofollow">Try my mock exam.</a>
It is sorta covered in the JavaRanch Style Guide.
subject: A question about equals() method
It's not a secret anymore!