連想配列 perl

## 空のハッシュを作成
my %numbers = ();

my $uniq = "niigata";
# 要素を追加
$numbers{"tokyo"} = "13";
$numbers{"kanagawa"} = "14";
$numbers{$uniq}="15";

my ($key,$value);
if( exists($numbers{"saitama"}) ){
print "saitama exists. value is '$numbers{'saitama'}'\n";
} else {
print "saitama NOT exists.\n";
}

while ( ( $key, $value ) = each( %numbers ) ) {
print "$key : $value\n";
}
print "-----------------\n";