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.
seems like you have learned C/C++ language & you are thinking in those terms. in java if you were to declare int  arr = new int; it will run properly as it requires atleast one, that is the highest dimension of the array to be created. the rest you can leave it blank. you can assign as and when you require arr = new int; arr = new int ;
the arrays need have all its dimensions the same length!! arr.length is 3 arr.length is 5 arr.length is 2