arrays - Swift 结构错误

Question

我正在尝试创建一个有趣的事实应用程序。它每次都会显示数组中的随机字符串，然后从数组中删除该事实。对于我的代码，当应用程序首次启动时，它会获取新的事实数组，并在应用程序关闭时保存数据，并在每次初始启动后使用上次启动时的数组。我的问题是我在代码的倒数第四行收到错误“调用中缺少参数 #1 的参数”。请帮助我，我对编程还很陌生。

import Foundation
let userDefaults = NSUserDefaults.standardUserDefaults()

func isAppAlreadyLaunchedOnce()->Bool{
    let defaults = NSUserDefaults.standardUserDefaults()

    if let isAppAlreadyLaunchedOnce = defaults.stringForKey("isAppAlreadyLaunchedOnce"){
        println("App already launched")
        return true
    }
    else{
        defaults.setBool(true, forKey: "isAppAlreadyLaunchedOnce")
        println("App launched first time")
        return false
    }
}

struct newFactBook {


    let factsArray = [
        "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."]

}

    var checkLaunch = isAppAlreadyLaunchedOnce()
    var oldFunFactsArray = []

    if(checkLaunch == false){
    oldFunFactsArray = newFactBook().factsArray
    }

    else if (checkLaunch == true){
    oldFunFactsArray = userDefaults.objectForKey("key") as! NSArray
    }



struct returnRandomFacts {
    func randomFacts() -> (String, Int){
        var unsignedArrayCount = UInt32(oldFunFactsArray.count)
        var unsignedRandomNumber = arc4random_uniform(unsignedArrayCount)
        var randomNumber = Int(unsignedRandomNumber)
        return (oldFunFactsArray[randomNumber] as! String, randomNumber)

    }
}

returnRandomFacts.randomFacts().1 // error right here
println(oldFunFactsArray)
userDefaults.setObject(oldFunFactsArray, forKey:"key")
userDefaults.synchronize()

Answer 1

您需要初始化returnRandomFacts。尝试以下returnRandomFacts().randomFacts().1