Enumeration interface

■ Enumerations are used for Vector (which is a List) and Stack (also a List).

■ You must always explicitly cast all returned elements.

■ You cannot remove elements with Enumerations (unlike with the newer iterators)

.elements( ), .hasMoreElements( ) and .nextElement( ) methods

■ vh.elements( ) returns an enumerator. i.e. assume a Vector v

Enumeration e = v.elements( );

while (e.hasMoreElements( )) {

if ( (ObjectCastHere) (e.nextElement( ) ) == gotcha) then do something; }

or ... Object element = (YourObjectCast) e.nextElement( );

■ e.nextElement( ) throws a NoSuchElementException after the end, so you need a try-catch here.

import java.util.*;

try {

Vector v = new Vector( );

v.add( "AA" );

v.add( "BB" );

v.add( "CC" );

v.add( "DD" );

Enumeration e = v.elements( );

while ( e.hasMoreElements( ) ) {

Object element = (Object) e.nextElement( );

System.out.println(element); } //prints => AA BB CC DD

}

catch (Exception e) { }