如何在Swift

Question

我对Swift和编程一般都是新手，所以在我试图掌握这一点时请耐心等待。

我一直在从Treehouse学习Swift的初学者课程，并设法开发一个生成随机引号的简单应用程序。到现在为止还挺好。现在，在进入更高级的课程之前，我想我会尝试更新现有的应用程序，以确保在继续之前获得一些可靠的练习。

所以这是我的问题：我已经设法通过GameKit框架生成一个随机数，但问题是有时引号连续出现。我怎样才能避免这种情况发生？

这是我的代码：

import GameKit

struct FactProvider {
    let facts = [
        "Ants stretch when they wake up in the morning.",
        "Ostriches can run faster than horses.",
        "Olympic gold medals are actually made mostly of silver.",
        "You are born with 300 bones; by the time you are an adult you will have 206.",
        "It takes about 8 minutes for light from the Sun to reach Earth.",
        "Some bamboo plants can grow almost a meter in just one day.",
        "The state of Florida is bigger than England.",
        "Some penguins can leap 2-3 meters out of the water.",
        "On average, it takes 66 days to form a new habit.",
        "Mammoths still walked the Earth when the Great Pyramid was being built."
    ]

    func randomFact() -> String {
        let randomNumber = GKRandomSource.sharedRandom().nextInt(upperBound: facts.count)
        return facts[randomNumber]
    }
}

Answer 1

您可以将最后一个随机数或最后一个事实存储在变量中，并在randomFact函数中进行检查。像这样：

var lastRandomNumber = -1

func randomFact() -> String {
    let randomNumber = GKRandomSource.sharedRandom().nextInt(upperBound: facts.count)

    if randomNumber == lastRandomNumber {
        return randomFact()
    } else {
        lastRandomNumber = randomNumber
        return facts[randomNumber]
    }
}