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.
Which of the following types can be added to java.util.Vector? A) reference B) null C) int D) All of the above The answer given in the mock are A, B. When I verified I am able to add null to Vector. Are there any other collection classes where I can add null?