PHP, 29 Bytes
<?=strlen($argn)-($argn<"0");
PHP, 32 Bytes
<?=preg_match_all("#\d#",$argn);
35 Bytes
<?=strlen($argn)-strspn($argn,"-");
<?=strlen($argn)-($argn<"0");
<?=preg_match_all("#\d#",$argn);
<?=strlen($argn)-strspn($argn,"-");