This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Hi!everyone. 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"?