用GKRandomSource生成随机数

Question

I am using GKRandomSource in a struct to return a random inspirational quote in the view. Is there a way to return that random number and omit the prior entry? That way the user doesn't receive the same quote twice in a row.

let inspiration = [
    "You are looking rather nice today, as always.",
    "Hello gorgeous!",
    "You rock, don't ever change!",
    "Your hair is looking on fleek today!",
    "That smile.",
    "Somebody woke up on the right side of bed!"]

func getRandomInspiration() -> String {
    let randomNumber = GKRandomSource.sharedRandom().nextIntWithUpperBound(inspiration.count)
    return inspiration[randomNumber]
}

Answer 1

To keep from generating the same quote, keep track of the last one in a struct property called lastQuote . Then reduce the max random number by 1, and if you generate the same as the lastQuote , use max instead.

struct RandomQuote {
    let inspiration = [
        "You are looking rather nice today, as always.",
        "Hello gorgeous!",
        "You rock, don't ever change!",
        "Your hair is looking on fleek today!",
        "That smile.",
        "Somebody woke up on the right side of bed!"]

    var lastQuote = 0

    mutating func getRandomInspiration() -> String {
        let max = inspiration.count - 1
        // Swift 3
        // var randomNumber = GKRandomSource.sharedRandom().nextInt(upperBound: max)
        var randomNumber = GKRandomSource.sharedRandom().nextIntWithUpperBound(max)
        if randomNumber == lastQuote {
            randomNumber = max
        }
        lastQuote = randomNumber
        return inspiration[randomNumber]
    }
}

var rq = RandomQuote()
for _ in 1...10 {
    print(rq.getRandomInspiration())
}