use strict;
use warnings;

print "These are the ", scalar @ARGV, " arguments:\n";
my $i = 0;
for (@ARGV) {
    print "ARGV[$i] = $_\n";
    $i++;
}

##</code><code>##

These are the 4 arguments:
ARGV[0] = s/foo/bar/
ARGV[1] = file1.txt
ARGV[2] = file2.txt
ARGV[3] = file3.txt

##</code><code>##

use strict;
use warnings;
use Data::Dumper;
print Dumper(\@ARGV);

##</code><code>##

$VAR1 = [
          's/foo/bar/',
          'file1.txt',
          'file2.txt',
          'file3.txt'
        ];

##</code><code>##

use strict;
use warnings;

my $op = shift;
# same as: my $op = shift @ARGV;

print "These are the ", scalar @ARGV, " arguments:\n";
my $i = 0;
for (@ARGV) {
    print "ARGV[$i] = $_\n";
    $i++;
}

##</code><code>##

These are the 3 arguments:
ARGV[0] = file1.txt
ARGV[1] = file2.txt
ARGV[2] = file3.txt