File Doc Category Size Date Package
Iterator.java API Doc Java SE 6 API 2174 Tue Jun 10 00:25:54 BST 2008 java.util

Iterator

public interface Iterator

An iterator over a collection. Iterator takes the place of Enumeration in the Java collections framework. Iterators differ from enumerations in two ways:

Iterators allow the caller to remove elements from the underlying collection during the iteration with well-defined semantics.
Method names have been improved.

This interface is a member of the Java Collections Framework.

author: Josh Bloch
version: 1.27, 07/24/06
see: Collection
see: ListIterator
see: Enumeration
since: 1.2

Fields Summary
Constructors Summary
Methods 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.)
return
true if the iterator has more elements.
public E next()
Returns the next element in the iteration.
return
the next element in the iteration.
exception
NoSuchElementException iteration has no more elements.
public void remove()
Removes from the underlying collection the last element returned by the 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.
exception
UnsupportedOperationException if the remove operation is not supported by this Iterator.
exception
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.