Actually, you get a syntax error there, but only because you're missing the if keyword :-)

But you're correct; you don't get a warning.  And that's because you're not trying to use the value of $baseball{yankees}, you're only modifying it (ie. appending to it).

Note that you do get a warning if $baseball{mets} is undefined, as in: 


use strict;
use warnings;

my %baseball = (
    orioles   =>   "baltimore",
    twins     =>   "minnesota"
);

if ($baseball{yankees} .= $baseball{mets})  {
    foreach $_ (keys %baseball) {
        print "$_ => $baseball{$_}\n";
    }
}

__END__
Use of uninitialized value in concatenation (.) or string at test.pl l
+ine 10.

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s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/

In reply to Re^2: problem unless I use ".=" by liverpole
in thread problem unless I use ".=" by cgmd

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