Remove Whitespace before and after comma

[conware]

Hi guys,

I was wondering if its possible with preg_replace to remove whitespace before and after a comma and limit words in a string to have atleast 3 letters?

this, is, a , test , string   ,

Could I change the above string into this:

this, is, a, test, string,

with preg_replace?

My current preg_replace looks like this:

<?php
$string = 'this, is, a , test , string   , ';
$string = preg_replace('/[^a-zA-Z0-9\s,]/', '', $string);
?>

Thanks for any help.

[sunfighter]

Simpler:

$my = str_replace(' , ', ', ', "this, is, a , test , string   ,");
echo $my; 

[conware]

Thanks for the reply sunfighter