Client and backend. This class is shared: the same code is compiled into your app and into your server, so everything on this page works in both.

public interface Iterator<E>

Known subtypesForm.TabIterator, ListIterator, PrimitiveIterator, PrimitiveIterator.OfDouble, PrimitiveIterator.OfInt, PrimitiveIterator.OfLong

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.

Type parameter E: the type of object returned by the iterator.

Methods

public abstract boolean hasNext()Returns whether there are more elements to iterate, i.e. whether the iterator is positioned in front of an element.
public abstract 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.
public default void remove()Removes the last element next answered from the collection being iterated, which this iterator does not support unless it says otherwise.
public default void forEachRemaining(Consumer<? super E> action)Hands each remaining element to action, in order.

Method details

hasNext

public abstract 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

public abstract 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

remove

public default void remove()
Removes the last element next answered from the collection being iterated, which this iterator does not support unless it says otherwise.

Throws

UnsupportedOperationException
when removing is not supported
IllegalStateException
when next has not been called, or remove has already been called after the last call to next

forEachRemaining

public default void forEachRemaining(Consumer<? super E> action)
Hands each remaining element to action, in order.