preg_replace to remove all words beginning with http:// and ending with a space

[HonoAduraro]

i got an idea to remove all links from a string with PHP.i need a preg_replace to remove and strip all words beginning with :http:// or https:// or www. or www3. or ftp://and ending with a white space.example : hello http://dsqdsq.com/fdsfsd?fsdflsd enjoy !it's will be : hello enjoy !Thanks