- print_r: documentation ( source)
- sort: documentation ( source)
<?php
$testArray = array('PW_PG3_COKE_A.jpg','2DAYSALEGATE_PG2.jpg','PWBY4_DELI-1.jpg','PW_PG2_COKE_A.jpg','2DAYSALEGATE_PG1.jpg','722_PG1.jpg');
sort($testArray, SORT_NATURAL | SORT_FLAG_CASE);
print_r($testArray);