Java in a Nutshell, 5th Edition

Name

Enumeration<E>

Synopsis

This interface defines the methods necessary to enumerate, or iterate, through a set of values, such as the set of values contained in a hashtable. This interface is superseded in Java 1.2 by the Iterator inteface. In Java 5.0 this interface has been made generic and defines the type variable E to represent the type of the objects being enumerated.

An Enumeration is usually not instantiated directly, but instead is created by the object that is to have its values enumerated. A number of classes, such as Vector and Hashtable, have methods that return Enumeration objects.

To use an Enumeration object, you use its two methods in a loop. hasMoreElements( ) returns true if there are more values to be enumerated and can determine whether a loop should continue. Within a loop, a call to nextElement( ) returns a value from the enumeration. An Enumeration makes no guarantees about the order in which the values are returned. The values in an Enumeration can be iterated through only once; there is no way to reset it to the beginning.

public interface Enumeration<E> {
// Public Instance Methods
     boolean hasMoreElements( );  
     E nextElement( );  
}

Implementations

StringTokenizer

Passed To

java.io.SequenceInputStream.SequenceInputStream( ), Collections.list( )

Returned By

Too many methods to list.