Reverse LinkedList in java

Question

I need to understand simple example

 LinkedList list = new LinkedList();
        list.add("J");
        list.add("A");
        list.add("V");
        list.add("A");

I have simple LinkedList and need pass it to method reverse

public void reverse(LinkedList list) {

}

which will return reversed new list

and I do not need any ArraysUtils for reversing it

what is the short and practice way for having reversed output.

The same needed understand also for simple arrays.

Answer 1

You can use the Collections class.

Collections.reverse(list);

Your list will be reversed after that operation.

Answer 2

public void reverse(LinkedList list) {
    //run till middle and swap start element with end element and so on
    for(int i = 0, mid = list.size()/2, j = list.size() - 1; i < mid; i++, j--)
        list.set(i, list.set(j, list.get(i)));//swap
}

Note: List.set(..,..) method returns the element previously at the specified position