%hash = ( Karl => 2,
Joe => 3,
Shawn => 0,
Paul => 1,
Bill => undef );
# obtain the list of hashKeys and display each key-value pair
@hashKeys = keys( %hash );
for ( $i = 0; $i < @hashKeys; ++$i ) {
print "$hashKeys[ $i ] => $hash{ $hashKeys[ $i ] }\n";
}
delete( $hash{ 'Joe' } );
while ( $key = pop( @hashKeys ) ) {
print "\n";
# determine if a particular key exists
if ( exists( $hash{ $key } ) ) {
print "$key exists in the hash.\n";
}
else {
print "$key doesn't exist in the hash.\n";
}
}