java.util.Iterator Maven / Gradle / Ivy
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This work corresponds to the API signatures of JSR 219: Foundation
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*/
package java.util;
/**
* 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 1.14, 02/02/00
* @see Collection
* @see ListIterator
* @see Enumeration
* @since 1.2
*/
public interface Iterator
{
/**
* 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 boolean hasNext();
/**
* Returns the next element in the iteration.
*
* @return the next element in the iteration.
* @exception NoSuchElementException iteration has no more elements.
*/
public Object next();
/**
*
* 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.
*/
public void remove();
}