perl default var

a.pl

while (<>) {
  chomp;
  print;
}

arr.pl

use v5.14;

my @arr = (10, 20, 30, 20, 25);
my $sum = 0;

foreach my $el (@arr) {
    $sum += $el;
}

foreach (@arr) {
    $sum += $_;
}

$sum += $_ for (@arr);

test.pl

use v5.14;

my @ext = qw/*.txt *.c/;

unlink glob for (@ext);