I tried: ... And the end results were the same.

$Person1, $Person2 are not the problem

The problem is %Pairs and %PairsOf

$PairsOf{$Person1} is not defined (it is uninitialized), but you assign to it the value of $PairsOf{$Person1} (an uninitialized value)

Its like writing 

my $foo = undef;
my $bar = 'bar';
$foo = $foo . $bar; # UNITIALIZED!!!

[download]

Get it?

In reply to Re^2: need help to fix "use of uninitialized value..." by Anonymous Monk
in thread need help to fix "use of uninitialized value..." by mlebel

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