in reply to Throw compilation error(or warning) if duplicate keys are present in hash

use strict;
use warnings;

my %hash = ("one" => "1",
          "two" => "2",
          "one" => "3",
        );

foreach my $key ( keys %hash ) {
    print $key, " => ", $hash{$key}, "\n";
}

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output
one => 3
two => 2

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unable to track the dublicate key.filtration done by perl itself
nice point by i_love_perl

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Re^2: Throw compilation error(or warning) if duplicate keys are present in hash
by ikegami (Patriarch) on Nov 25, 2011 at 04:02 UTC 
    %hash = EXPR;

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    does something like 
    my @anon = LIST;
%hash = ();
while (@anon) {
   my $k = shift(@anon);
   my $v = shift(@anon);
   $hash{$k} = $v;
}

    [download]

    So if you have two values for the same key, the latter prevails.

    (There's no actual @anon created; the stack is used.)

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