Which fingers do I use to pluck?

Sorry in advance if this is the wrong section.
So I've been playing guitar for around 4 years and I just picked up a ukulele yesterday. Do you use a different finger for each string? Like thumb for first, index secong, middle third, and ring last string? Or is it thumb for more than one, or index for more than one, etc.?

Can someone give me an example of what there picking hand would do for the first 4 measures of this?

http://ukulelehunt.com/wp-content/uploads/2007/12/rudolph.pdf

Thanks

It seems there is no answer to this other than do what works for you...

"Do you use a different finger for each string? Like thumb for first, index secong, middle third, and ring last string?"

That is the way I do some songs but not others.

I think it all depends on your ability and comfortability level. Ideally, you can use your thumb, index, middle, and ring finger which most guitarists do. I just use my thumb and index finger, occasionally the middle finger.

I usually use my thumb for all of the strings, but for some songs, such as the intro to Jake Shimabukuro's Dragon, it is necessary to assign each finger a different string.