如何在swift中初始化我的數組

Question

我有這個問題和答案應用程序的代碼，我想。它應該問陣列中的一個隨機問題。 我的代碼在操場上工作，但是當我將它放入一個xcode項目時，它告訴我：

無法在屬性初始值設定項中使用實例成員'Kat1'屬性初始值設定項在'self'可用之前運行

Im新編程應用程序和swift，我不知道如何以正確的方式初始化數組。

這裏是代碼即時通訊使用：

var Kat1: [(question: String, answer: String)] = 
    [ 
     ("What is the capital of Alabama?", "Montgomery"), 
     ("What is the capital of Alaska?", "Juneau"), 
     ("What is the capital of Test?", "Test Town") 
] 

var antal = (Kat1.count) 
var randomtal = Int(arc4random_uniform(UInt32(antal))) 

print(Kat1[randomtal].question) 
print(Kat1[randomtal].answer)` 

我到底做錯了什麼？

Answer 1

把你的代碼的函數裏面....

override func viewDidLoad() { 
    super.viewDidLoad() 

var Kat1: [(question: String, answer: String)] = 
[ 
    ("What is the capital of Alabama?", "Montgomery"), 
    ("What is the capital of Alaska?", "Juneau"), 
    ("What is the capital of Test?", "Test Town") 
] 

var antal = (Kat1.count) 
var randomtal = Int(arc4random_uniform(UInt32(antal))) 

print(Kat1[randomtal].question) 
print(Kat1[randomtal].answer)` 
} 

Answer 2

你可能要打包的問題和答案在一個結構，可容納所有這些，並根據要求提供的個別問題。這將允許您將存儲問題的代碼和提出問題的代碼分開。

struct Quiz { 
    var kat1: [(question: String, answer: String)] = 
     [("What is the capital of Alabama?", "Montgomery"), 
     ("What is the capital of Alaska?", "Juneau"), 
     ("What is the capital of Test?", "Test Town")] 

    func randomQuestion() -> (question: String, answer: String) { 
     let randomtal = Int(arc4random_uniform(UInt32(kat1.count))) 
     return kat1[randomtal] 
    } 
} 

let quiz = Quiz() 
let qa = quiz.randomQuestion() 
print(qa.question) 
print(qa.answer)