<?
$number_key_array = array(
12345 => "Foo",
123451234512345 => "Bar",
123451234512345123451234512345 => "Baz"
);
var_dump($number_key_array);
$string_key_array = array(
"12345" => "Foo",
"123451234512345" => "Bar",
"123451234512345123451234512345" => "Baz"
);
var_dump($string_key_array);