Thanks people - that did the trick ! I've tested out both and they work. But perhaps for me, this is more obvious and will make it easier for me to work out exactly what I'm doing here, should I need to look back on it:

foreach my $ip ( keys %subnets ) {
    $subnets{$ip}{comment} //= 'ALLOCATED';
}

[download]

Thanks again

In reply to Re: Check/set hash of hashes value by stroke
in thread Check/set hash of hashes value by stroke

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