OpenJDK 27 · java.util.Iterator · APIdia, the JavaDoc alternative

Method Summary

Modifier and Type	Method and Description
public default void	forEachRemaining(Consumer<? super E> The action to be performed for each element action) Performs the given action for each remaining element until all elements have been processed or the action throws an exception.
public boolean	Returns: `true` if the iteration has more elements hasNext() Returns `true` if the iteration has more elements.
public E	Returns: the next element in the iteration next() Returns the next element in the iteration.
public default void	remove() Removes from the underlying collection the last element returned by this iterator (optional operation).

Method Detail

forEachRemaining back to summary

forEachRemaining	back to summary
public default void forEachRemaining(Consumer<? super E> action) Performs the given action for each remaining element until all elements have been processed or the action throws an exception. Actions are performed in the order of iteration, if that order is specified. Exceptions thrown by the action are relayed to the caller. The behavior of an iterator is unspecified if the action modifies the collection in any way (even by calling the `remove` method or other mutator methods of `Iterator` subtypes), unless an overriding class has specified a concurrent modification policy. Subsequent behavior of an iterator is unspecified if the action throws an exception. Implementation Specification The default implementation behaves as if: `while (hasNext()) action.accept(next());` Parameters action:Consumer<? super E> The action to be performed for each element Exceptions NullPointerException: if the specified action is null Since 1.8

public default void forEachRemaining(Consumer<? super E> action)

Performs the given action for each remaining element until all elements have been processed or the action throws an exception. Actions are performed in the order of iteration, if that order is specified. Exceptions thrown by the action are relayed to the caller.

The behavior of an iterator is unspecified if the action modifies the collection in any way (even by calling the remove method or other mutator methods of Iterator subtypes), unless an overriding class has specified a concurrent modification policy.

Subsequent behavior of an iterator is unspecified if the action throws an exception.

Implementation Specification

The default implementation behaves as if:

while (hasNext())
        action.accept(next());

Parameters

action:Consumer<? super E>: The action to be performed for each element

Exceptions

NullPointerException:: if the specified action is null

Since

1.8

hasNext back to summary

hasNext	back to summary
public boolean hasNext() Returns `true` if the iteration has more elements. (In other words, returns `true` if `next` would return an element rather than throwing an exception.) Returns:boolean `true` if the iteration has more elements

public boolean hasNext()

Returns true if the iteration has more elements. (In other words, returns true if next would return an element rather than throwing an exception.)

Returns:boolean: true if the iteration has more elements

next	back to summary
public E next() Returns the next element in the iteration. Returns:E the next element in the iteration Exceptions NoSuchElementException: if the iteration has no more elements

back to summary

public E next()

Returns the next element in the iteration.

Returns:E

the next element in the iteration

Exceptions

NoSuchElementException:: if the iteration has no more elements

remove back to summary

remove	back to summary
public default void remove() Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to `next`. The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method, unless an overriding class has specified a concurrent modification policy. The behavior of an iterator is unspecified if this method is called after a call to the `forEachRemaining` method. Implementation Specification The default implementation throws an instance of `UnsupportedOperationException` and performs no other action. Exceptions UnsupportedOperationException: if the `remove` operation is not supported by this iterator IllegalStateException: if the `next` method has not yet been called, or the `remove` method has already been called after the last call to the `next` method

public default void remove()

Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to next.

The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method, unless an overriding class has specified a concurrent modification policy.

The behavior of an iterator is unspecified if this method is called after a call to the forEachRemaining method.

Implementation Specification

The default implementation throws an instance of UnsupportedOperationException and performs no other action.

Exceptions

UnsupportedOperationException:: if the remove operation is not supported by this iterator
IllegalStateException:: if the next method has not yet been called, or the remove method has already been called after the last call to the next method

public Interface Iterator<E>

Method Summary

Method Detail