Because that's the way it works. From perldata: 
       You may assign to undef in a list.  This is useful for
       throwing away some of the return values of a function:

           ($dev, $ino, undef, undef, $uid, $gid) = stat($file);

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-- Randal L. Schwartz, Perl hacker

In reply to Re: undef as an lvalue by merlyn
in thread undef as an lvalue by MrNobo1024

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