use constant {
    NULL => 0,
    EINS => 1,
    ZWEI => 2,
};
my %english_translation = (
    NULL => "Zero",
    EINS => "One",
    ZWEI => "Two",
);

foreach ( keys %english_translation )
{
    print "$_ = $english_translation{$_}\n";
}


##</code><code>##

EINS = One
NULL = Zero
ZWEI = Two

##</code><code>##

0 = Zero
1 = One
2 = Three