Perl - Ways to recover @ARGV

#!/usr/bin/perl
use strict;
use warnings;

#ways to recover
print join (" | ",@ARGV),"\n";
print "$ARGV[0] - $ARGV[1] - $ARGV[2]\n";

result : argument [example for blog]

$ ./blog.pl example for blog
example | for | blog
example - for - blog

$./blog.pl
Use of uninitialized value $ARGV[0] in concatenation (.) or string at ./blog.pl line 10.
Use of uninitialized value in concatenation (.) or string at ./blog.pl line 10.
Use of uninitialized value in concatenation (.) or string at ./blog.pl line 10.
- -