java.util

Interface Iterator<E>

Type Parameters:

E - the type of object returned by the iterator.

All Known Subinterfaces:

ListIterator<E>

public interface Iterator<E>

An Iterator is used to sequence over a collection of objects. Conceptually, an iterator is always positioned between two elements of a collection. A fresh iterator is always positioned in front of the first element. If a collection has been changed since its creation, methods next and hasNext() may throw a ConcurrentModificationException. Iterators with this behavior are called fail-fast iterators.

Method Summary

Modifier and Type	Method and Description
boolean	hasNext() Returns whether there are more elements to iterate, i.e.
E	next() Returns the next object in the iteration, i.e.
void	remove() Removes the last object returned by next from the collection.

Method Detail

hasNext

boolean hasNext()

Returns whether there are more elements to iterate, i.e. whether the iterator is positioned in front of an element.

Returns:

true if there are more elements, false otherwise.

See Also:

next()

next

E next()

Returns the next object in the iteration, i.e. returns the element in front of the iterator and advances the iterator by one position.

Returns:

the next object.

Throws:

NoSuchElementException - if there are no more elements.

See Also:

hasNext()

remove

void remove()

Removes the last object returned by next from the collection. This method can only be called once after next was called.

Throws:

UnsupportedOperationException - if removing is not supported by the collection being iterated.

IllegalStateException - if next has not been called, or remove has already been called after the last call to next.