I'd use a for-loop if I were you. But a while-loop would probably do
just as well (subtle pun).

   - Oliver

I would use a 'for' loop.
http://java.sun.com/docs/books/tutorial/java/nutsandbolts/for.html

Carl.

As you say 'digit' I assume the range is [0;9], so

public static final String STAR9 = "*********";
...
  STAR9.substring( /*for you to figure out*/ );

As there are only 10 different scores, you could cache them in an array
so you don't create a new String object every time.

If you have larger numbers to deal with
use a StringBuffer to "double up"

public static final StringBuffer STARS = new StringBuffer("****");
...
  while (STARS.length()<score) STARS.append(STARS);
  STARS.substring( /*for you to figure out*/ );