$ perl -le 'my $s = ("111","bbb"); print $s'
bbb
$ perl -le 'my $s =  "111","bbb" ; print $s'
111
$ perl -MO=Deparse,-p -e 'my $s = ("111","bbb")'
(my $s = ('???', 'bbb'));
$ perl -MO=Deparse,-p -e 'my $s =  "111","bbb" '
((my $s = '111'), '???');

##</code><code>##

$ perl -wMstrict -e 'my $s = ("111","222","aaa","bbb")'
Useless use of a constant ("111") in void context at -e line 1.
Useless use of a constant ("222") in void context at -e line 1.
Useless use of a constant ("aaa") in void context at -e line 1.
$ perl -wMstrict -e 'my $s =  "111","222","aaa","bbb" '
Useless use of a constant ("222") in void context at -e line 1.
Useless use of a constant ("aaa") in void context at -e line 1.
Useless use of a constant ("bbb") in void context at -e line 1.