use strict;
use warnings;

my @testarray;
push @testarray, [10,20],[30,40];

print "ok...\n";
print "$#testarray\n";
print "$testarray[0]->[0]\n\n";

foreach(@testarray){
  while(<DATA>){
  }
}

print "Nope...\n";
print "$#testarray\n";
print "$testarray[0]->[0]\n";

__DATA__
hello
world

##</code><code>##

ok...
1
10

Nope...
1
Use of uninitialized value in concatenation (.) or string at test_02.pl line 17, <DATA> line 2.

##</code><code>##

map{$a=1-$_/10;map{$d=$a;$e=$b=$_/20-2;map{($d,$e)=(2*$d*$e+$a,$e**2
-$d**2+$b);$c=$d**2+$e**2>4?$d=8:_}1..50;print$c}0..59;print$/}0..20