HashMap1public class HashMap1 extends Object | Construction, enumeration, access, rejection of duplicates. |
| Methods Summary |
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| public static void | main(java.lang.String[] args)
HashMap map = new HashMap();
map.add( new Integer( 2 ), "two" );
map.add( new Integer( 4 ), "four" );
System.out.println( map );
System.out.println();
System.out.println( "Enumerate the HashMap" );
Enumeration e = map.elements();
while ( e.hasMoreElements() )
System.out.println( e.nextElement() );
System.out.println();
System.out.println( "Iterate through the HashMap" );
for ( HashMapIterator i = map.begin(); !i.atEnd(); i.advance() )
System.out.println( i.get() + ", key = " + i.key() + ", value = " + i.value() );
System.out.println();
System.out.println( "Demonstrate access" );
System.out.println( "map.get( 2 ) = " + map.get( new Integer( 2 ) ) );
System.out.println( "map.get( 5 ) = " + map.get( new Integer( 5 ) ) );
System.out.println( "map = " + map );
System.out.println();
System.out.println( "Show that duplicates cannot be added." );
Object value = map.add( new Integer( 8 ), "eight" );
if ( value != null )
System.out.println( "Could not add 8." );
else
System.out.println( "Added 8." );
System.out.println( "map = " + map );
value = map.add( new Integer( 4 ), "FOUR" );
if ( value != null )
System.out.println( "Could not add 4." );
else
System.out.println( "Added 4." );
System.out.println( "map = " + map );
System.out.println();
System.out.println( "Demonstrate modification" );
map.put( new Integer( 4 ), "FOUR" );
System.out.println( "map = " + map );
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