[RESOLVED] strip extra commas

[zzz]

I get a data from a form field in the following format:

,,,,,856,,,,1029,,,,,,457,

I need to have it as:

856,1029,457

Now, I can trim the last and first ones with ltrim and rtrim. How do I clean the middle when I do not know how many commas there will be?

[laserlight]

Consider:

<?php
$str = ',,,,,856,,,,1029,,,,,,457,';
$str = preg_replace('/,+/', ',', trim($str, ','));
echo $str;
?>