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my @a

my @new_a;
for my $i (0..$#a){
...
}
@a = @new_a;
@new_a = ();

my @a = ("bob", "bob", "martha", "bob");
for my $i (0..$#a){
...
}
#@a is now ("bob", "martha"), but I don't want any "bob"s;
#also I get harassed about uniniatialized values when I use warnings