- substr_count: documentation ( source)
- explode: documentation ( source)
- strtoupper: documentation ( source)
<?php
$lot_num = strtoupper('e1,1,2,3,4,5,7,8,9,10,11,12,13,14,15,16,17,18,e18');
echo 'END UNIT: '.substr_count($lot_num, 'E');
Echo '\ntotal count: '. count(explode(",", $lot_num));
Echo '\nother count: '. count(explode(",", $lot_num))-intval(substr_count($lot_num, 'E'));