my $dim  = 3;
my @size = (4, 5, 6);
my $var  = 'a';
my $str  = '';

for my $i (0 .. $dim - 1) {
  $str .= '  ' x $i .
          "for my \$$var (0 .. $size[$i] - 1) {\n";
  $var++;
}

$var = 'a';
$str .= '  ' x $dim . '$array' .
        join '' => map {'[$ ' . $var++ . ']'} 1 .. $dim;
$str .= " = 0;\n";

$str .= "  " x ($dim - $_) . "}\n" for 1 .. $dim;