Java(TM) 2 Platform, Standard Edition, v1.2.2 API Specification: Interface Enumeration - JDK 5 Documentation v1.2.2, Java 2 SDK 英文文档

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java.util
Interface Enumeration

All Known Implementing Classes:: StringTokenizer

public interface Enumeration

An object that implements the Enumeration interface generates a series of elements, one at a time. Successive calls to the nextElement method return successive elements of the series.

For example, to print all elements of a vector v:

     for (Enumeration e = v.elements() ; e.hasMoreElements() ;) {
         System.out.println(e.nextElement());

     }

Methods are provided to enumerate through the elements of a vector, the keys of a hashtable, and the values in a hashtable. Enumerations are also used to specify the input streams to a SequenceInputStream.

NOTE: The functionality of this interface is duplicated by the Iterator interface. In addition, Iterator adds an optional remove operation, and has shorter method names. New implementations should consider using Iterator in preference to Enumeration.

Since:: JDK1.0
See Also:: Iterator, SequenceInputStream, nextElement(), Hashtable, Hashtable.elements(), Hashtable.keys(), Vector, Vector.elements()

Method Summary

boolean hasMoreElements()
Tests if this enumeration contains more elements.

Object nextElement()
Returns the next element of this enumeration if this enumeration object has at least one more element to provide.

Method Detail

hasMoreElements

public boolean hasMoreElements()

Tests if this enumeration contains more elements.

Returns:: true if and only if this enumeration object contains at least one more element to provide; false otherwise.

nextElement

public Object nextElement()

Returns the next element of this enumeration if this enumeration object has at least one more element to provide.

Returns:: the next element of this enumeration.
Throws:: NoSuchElementException - if no more elements exist.