#!/usr/bin/perl -w

use strict;

my @a;

$a[0] = 'a';
$a[3] = 'b';
$a[7] = 'c';

print "Iteration #1\n";
foreach my $v (@a) {
	print defined $v ? "$v " : "undef ";
}
print "\n";

print "\nIteration #2\n";
foreach my $i (0..$#a) {
	print "\$a[$i] = ", defined $a[$i] ? "$a[$i]" : "undef", "\n";
}
print "\n";

# simpler:

print "Iteration #3 (using \$_ default)\n";
for (@a) {
	print defined $_ ? "$_ " : "undef ";
}
print "\n";

print "\nIteration #4 (using \$_ default)\n";
for (0..$#a) {
	print "\$a[$_] = ", defined $a[$_] ? $a[$_] : "undef", "\n";
}