如何使用java.util.ListIterator输出保存对象的Linked List？

Question

Hi I got this problem with I am not sure how to deal with... I have a Linked List which stores Objects which works fine. But now I am trying to display the content of the linked list using iterator and I understand that wont be as simple as

ListIterator<String> iterator = LibraryUser.listIterator();  


iterator = LibraryUser.listIterator();
while (iterator.hasNext())
 System.out.println(iterator.next());

because of the type... Is there way to do this ?

OH RIGHT! I need to override toString don't i...

Answer 1

If all you know is that LibraryUser contains instances of Object (that is, you don't know that they are String instances), you can use:

ListIterator<Object> iterator = LibraryUser.listIterator();
while (iterator.hasNext()) {
    System.out.println(String.valueOf(iterator.next()));
}

or, more simply:

for (Object item : theList) {
    System.out.println(String.valueOf(item));
}

Answer 2

your code should work fine:

LinkedList<String> l = new LinkedList<>();
        l.add("aaa");
        l.add("sdjs");
        ListIterator<String> itr = l.listIterator();
        while(itr.hasNext()){
            System.out.println(itr.next());
        }

above code prints:

aaa
sdjs

Answer 3

Another approach would be to consider using the enhanced for-loop. Something like:

LinkedList<Object> list = new LinkedList<Object>();
list.add("abc");
list.add("def");
for(Object element: list){
    System.out.println(element);
}