替换多个“ - ”PHP [重复]

Possible Duplicate:
PHP Preg-Replace more than one underscore

Hi, I'm just wondering how I can replace 2 or more - signs in a string with just one in PHP.

So like

1-2---3--4

would go to

1-2-3-4

Thanks :)

Use preg_replace:

$str = preg_replace('/-+/', '-', $str);

No need regex

$text="1-2---3--4";
$s = implode("-",array_filter ( explode("-",$text) )) ;
print_r($s);