Preg_match using array?

Correct usage is: /,,([,]+)?|^,|,$|\b,\b|\s,/

$comma[0] = '/,,([,]+)?/';  
   开发者_JAVA百科         $comma[1] = '/^,/';     
            $comma[2] = '/,$/';
            $comma[3] = '/\b,\b/';  
            $comma[4] = '/\s,/';    

$analyst = preg_match($comma, $_POST['analyst']) 
    ? mysql_real_escape_string($_POST['analyst']) : NULL;

I am trying to detect commas from the users input, each regex is defined properly, but I do not understand why it isn't passing them into the if statement.

Edit:

if I change this:

$analyst = preg_match('test', $_POST['analyst']) 
    ? mysql_real_escape_string($_POST['analyst']) : NULL;

then it works, this makes no sense.

preg_match() doesn't accept arrays as arguments, only strings.

int preg_match ( string $pattern , string $subject [, array &$matches [, int $flags = 0 [, int $offset = 0 ]]] )

http://php.net/manual/en/function.preg-match.php

preg_match accept first parameter as string and you are passing an array.