php - Breaking Up a Formatted Number -

let have following formatting number string in php:

12,345,678.97

how break in php array following?

array (   [0] => 12,   [1] => ',',   [2] => '345',   [3] => ',',   [4] => '678',   [5] => '.',   [6] => '97' ); 

or

array (   [0] => 97,   [1] => '.',   [2] => '678',   [3] => ',',   [4] => '345',   [5] => ',',   [6] => '12' ); 

i want break string numbers broken groups , characters between groups of numbers broken out too. need in order automatically determine thousands/decimal separator in php currency strings.

using preg_split work in case:

// split @ non-number $arr = preg_split('/(\d)/', $str, -1, preg_split_delim_capture);