#!/usr/bin/perl

use strict;
use warnings;
no warnings 'uninitialized';

my @array = 1 .. 5;

$\ = "\n";

sub check {
	print "array length: " . @array;

	use tt;
	[% FOR check IN ["exists", "defined", "true", "" ] %]
	for my $i ( 0 .. $#array ) {
		print "[% check %]([$i]) is " . [% check %]( $array[$i] );
	}
	[% END %]
	no tt;

	print;
}

sub true { !!$_[0] }


check;
delete $array[$_] for 2 .. 3; # creates a hole
check;
undef $array[0]; # operates on the slot, not the array
check;
delete $array[-1]; # reduces length
check;
undef @array; # clears the array
check;
@array = 1 .. 3;
check;

##</code><code>##

array length: 5
exists([0]) is 1
exists([1]) is 1
exists([2]) is 1
exists([3]) is 1
exists([4]) is 1
defined([0]) is 1
defined([1]) is 1
defined([2]) is 1
defined([3]) is 1
defined([4]) is 1
true([0]) is 1
true([1]) is 1
true([2]) is 1
true([3]) is 1
true([4]) is 1
([0]) is 1
([1]) is 2
([2]) is 3
([3]) is 4
([4]) is 5

array length: 5
exists([0]) is 1
exists([1]) is 1
exists([2]) is 
exists([3]) is 
exists([4]) is 1
defined([0]) is 1
defined([1]) is 1
defined([2]) is 
defined([3]) is 
defined([4]) is 1
true([0]) is 1
true([1]) is 1
true([2]) is 
true([3]) is 
true([4]) is 1
([0]) is 1
([1]) is 2
([2]) is 
([3]) is 
([4]) is 5

array length: 5
exists([0]) is 1
exists([1]) is 1
exists([2]) is 1
exists([3]) is 1
exists([4]) is 1
defined([0]) is 
defined([1]) is 1
defined([2]) is 
defined([3]) is 
defined([4]) is 1
true([0]) is 
true([1]) is 1
true([2]) is 
true([3]) is 
true([4]) is 1
([0]) is 
([1]) is 2
([2]) is 
([3]) is 
([4]) is 5

array length: 4
exists([0]) is 1
exists([1]) is 1
exists([2]) is 1
exists([3]) is 1
defined([0]) is 
defined([1]) is 1
defined([2]) is 
defined([3]) is 
true([0]) is 
true([1]) is 1
true([2]) is 
true([3]) is 
([0]) is 
([1]) is 2
([2]) is 
([3]) is 

array length: 0

array length: 3
exists([0]) is 1
exists([1]) is 1
exists([2]) is 1
defined([0]) is 1
defined([1]) is 1
defined([2]) is 1
true([0]) is 1
true([1]) is 1
true([2]) is 1
([0]) is 1
([1]) is 2
([2]) is 3