sub foo_ize {
  for my $val (@_) {
    $val =~ s!bar!foo!gi;
  };
};

my @arr = qw( baz bar baz BarBar );
foo_ize @arr;
print join ",", @arr;

##</code><code>##

sub foo_ize_val {
  my @args = @_;
  map { s!foo!bar!ig; $_ } @args;
};

my @arr = qw( baz bar baz BarBar );
foo_ize @arr;
print join ",", @arr;
@arr = foo_ize @arr;
print join ",", @arr;