? and :

[Python523]

My friend had sent me a script that was like this:

NPC Code:

---

if (playertouchsme){

playerdarts = (playerdarts>=70? 99: playerdarts+30);

}

---

Could someone please explain what each part of that does like the ? and the 99: and how to use it? I think it has something to do with rounding numbers down but I couldn't figure out how it worked, any help would be greatly appreciated