We can also specify a range of values for charlist.

<?php
$str = "Hello fri3nd, you're
       looking          good today! 
       look1234ing";
print_r(str_word_count($str, 1, '0..3'));
?>

will give the result as 

Array ( [0] => Hello [1] => fri3nd [2] => you're [3] => looking [4] => good [5] => today [6] => look123 [7] => ing )