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Re^3: How to get Keys from hash having same value?

by shmem (Chancellor)
on Jan 07, 2008 at 14:19 UTC ( #660833=note: print w/replies, xml ) Need Help??


in reply to Re^2: How to get Keys from hash having same value?
in thread How to get Keys from hash having same value?

Voilà:
%newhash = reverse do { my $hash = reverse %myhash; %hash };

To get the keys only (which are the values in the reversed hash:

@unique_keys = do { my $hash = reverse %myhash; values %hash };

update: oops, got it all wrong. It' about getting all keys where duplicate values are found. As a single statement, formatted for readability

%myhash = (1 => 'a', 2=> 'b', 3=> 'a', 4=>'c',5 => 'b', 6 => 'a'); @k = do { my %s; map { my $v=$_; grep { $myhash{$_} eq $v} keys %myhash } grep {$s{$_}++==1} values %myhash }; print "$_ => $myhash{$_}\n" for @k; __END__ 6 => a 1 => a 3 => a 2 => b 5 => b

Ah well. Readability... ;-)

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

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