CODEWITHSUNDEEP
javaiterator
user7703770
user7703770

Reputation: 91

remove method throws error in List interface iterator

I am trying to use remove method but I am getting messed up as I keep getting error for this:

 List<String> list1 = new ArrayList<String>();
      list1.add("Apple");
      list1.add("Bus");
      list1.add("Cat");
      list1.add("Dog");
      String ne = list1.listIterator().next();
System.out.println(ne);
list1.listIterator().remove();

the remove statement throws an error?? can anyone tell me why?? same thing when I just use iterator in place of listIterator?

Upvotes: 2

Views: 143

Answers (1)

Tim Biegeleisen
Tim Biegeleisen

Reputation: 521239

Your code is correct in that you are allowed to call ListIterator#remove() once for each time next() is called (see Javadoc). However, in your code you are actually calling remove() on a new list iterator, not the one you used before it. Try the following code and hopefully it will be clear what you did wrong:

List<String> list1 = new ArrayList<String>();
list1.add("Apple");
list1.add("Bus");
list1.add("Cat");
list1.add("Dog");
// retain a reference to the same list iterator
ListIterator<String> list1itr = list1.listIterator();
String ne = list1itr.next();
System.out.println(ne);
list1itr.remove();

Demo

Upvotes: 3

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