regex - php preg_match() code for comma separated names -

i need validate input patterns using preg_match() patterns " anyname1,anyname2,anyname3, ".

note there comma @ end too. letter or number valid between commas, numbers not have appear @ end. e.g "nam1e,na2me,nnm22," valid.

i tried ^([a-za-z0-9] *, *)*[a-za-z0-9]$ did no work. have gone through other posts did not perfect answer.

can give me answer this?

it sounds want validate string contains series of comma separated alpha-numeric substrings, optional trailing comma.

in situation, should achieve want.

$str = "anyname1,anyname2,anyname3,";  $re = '~^([a-z0-9]+,)+$~i';  if (preg_match($re, $str)) {     // string matches pattern! } else {     // nope! } 

if value stored in $str contains trailing space in example, , don't want use trim() on value, following regex allow whitespace @ end of $str:

~^([a-z0-9]+,)+\s*$~i