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iosswiftarc4random

Impose limitations on arc4random()?

In Swift, I am using arc4random to generate a number between 0 and 568.

I need it impose limitations on this however. For example, the number can't be between 10 and 40. How are these "limitations" added?

Solution

  • Just keep trying until the condition is met:

    func funnyRandom() -> UInt32 {
    var ran: UInt32 = 0
    do {
        ran = arc4random_uniform(568)
    } while (ran > 10 && ran < 40)
    return ran;
}

    In Objective-C, it is the same method as in Swift:

    - (int)funnyRandom {
    int ran;
    do {
        ran = arc4random_uniform(568);
    } while (ran > 10 && ran < 40);
    return ran;
}