- print_r: documentation ( source)
- sort: documentation ( source)
<?php
$a=['W1010','W108','W109','W1011'];
$b=['W0010','W008','W009','W0011'];
sort($a,SORT_NATURAL);
sort($b,SORT_NATURAL);
print_r($a); # Sort OK
print_r($b); # Sort Wrong - Why? Bug?