Does putting a screen protector on your cracked screen keep it from getting worse?

So I cracked my iphone screen a couple weeks ago… I know, it sucks. Anyway, I put a screen protector on it and a full case to keep the cracking from getting worse. Will this also keep the phone from getting messed up inside? I have a friend who also cracked her phone and did nothing about it, and its gotten to the point that her keyboard doesn't always work. Is it because she just left her phone exposed like that? How long can I keep my phone like this before I get the screen replaced?

It would be no more than a bandaid… It may help for a while, but it won't really prevent further damage. Best to get the screen fixed as soon as you can.

No it won't really help, a screen protector is mainly for scratches. A case is what you'll want to prevent anymore cracks. If your screen cracks anymore, the screen protector will maybe just keep it in place. Sort of like the wiring you see in your school windows. It'll just keep it in place. You, might want to get a new screen and get a really good case brand like OtterBox. They make really good cases. It might be between from 40-70$ but its worth every penny.