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POJava - remove() in custom iterator and linked list
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copied!<p>I am an absolute Java beginner, and have been working on getting the remove() for a custom iterator (for a linked list) working. I have been trying for many hours getting this to work. My issue is that the iterated items are not removed. The method does however (correctly) throw an IllegalState-error, when there is no previous element.</p> <p>I would appreciate if you guys could have a look at it, and indicate what may be wrong, because I cannot work myself around it, and have tried all kinds of different things. One question: is the problem that I set next as head in constructor? Because if I don't, the list is not iterated at all! </p> <p>Thank you so much in advance.</p> <p>====================================================================</p> <pre><code>public class CustListIterator<E> implements Iterator<E> { private Node<E> head; private Node<E> next; private Node<E> prev; private CustList<E> list; public CustListIterator(CustList<E> list) { this.list = list; head = list.head; next = head; } public boolean hasNext() { return next != null; } public E next() { if (!hasNext()) throw new NoSuchElementException (); prev = next; E element = next.element; next = next.next; return element; } public void remove() { if(prev == null) { throw new IllegalStateException(); } else { if(prev == head){ head = prev.next; list.head = head; } next = prev.next; prev = null; list.listSize--; } } </code></pre> <p>=============================================================================</p> <p>Iteration of</p> <pre><code>CustList<String> items = new CustList<String>(); items.add("aaaaaa"); items.add("bbbbb"); items.add("ccc"); items.add("dddddddd"); items.add("eeeeee"); System.out.println("List iterated:"); Iterator<String> it = items.iterator(); while (it.hasNext()) { System.out.println(it.next()); it.remove(); } System.out.println("Size: " + items.size()); </code></pre> <p>=============================================================================</p> <p>Still gives however</p> <pre><code>List iterated: aaaaaa bbbbb ccc dddddddd eeeeee Size: 0 </code></pre>

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