Hızlı yanıt: kod örneği
As you've stated,arc4random returns an unsigned integer up to (2^32)-10xFFFFFFFF is equal to (2^32)-1, which is the largest possible value of . So the arithmetic expression gives you a ratio that is always between 0 and 1 — and as this is an integer division, the result can only be between 0 and 1.
arc4random()
(arc4random() / 0xFFFFFFFF)