an interesting technique but all it amounts to is testing for the existence of a hash element, which can also be done (perhaps more intuitively) thus:

my %lines;

while (<DATA>) {
        unless (exists($lines{$_})) {print "$_"}
        $hash{$_}="done";   # element defined
}

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In reply to Re: Why does this hash remove duplicate lines by halfcountplus
in thread Why does this hash remove duplicate lines by kangaroobin

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