hey i have a non fixed size list of main catogeries and from each catogory i will have non fixed size list of items what i need to use for this LinkedList or ArrayList or Vactor , ..etc? note this list will be wriiten to desk thx
LinkedList, ArrayList, Vector are all implementations of the interface List (in the package java.util). For the functionality of the program, it doesn't really matter which implementation you use - they should all have the same behaviour (functionally).
Which one is best depends on non-functional requirements. For example, LinkedList is more efficient than ArrayList when you often want to insert elements in the middle of the list, and ArrayList is more efficient than LinkedList when looking up elements by index; Vector is synchronized, while ArrayList and LinkedList are not (which is important when writing multi-threaded programs).
If you're just trying to get your program to work (and you're not yet in the stage of optimizing it), it doesn't really matter which implementation of List you choose.