我创建了一个名为“questions”的数组，其中充满了结构“QuizQuestion”的实例 - 基本上我希望“nextQuestion”函数从结构数组(问题)中提取下一个问题并将其显示给用户(我了解如何通过标签等呈现数据，我只是不知道如何访问它)。
我尝试调用数组索引，然后调用实例，但这似乎不起作用。我还尝试创建一个“QuizQuestion”实例作为变量，并在“NextQuestion”函数中使用它，该函数有效，但我不知道如何自动从“问题”中提取问题。
谢谢
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var questionLabel: UILabel!
@IBOutlet weak var answerLabel: UILabel!
@IBOutlet weak var explanationLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
questionVariable()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
struct QuizQuestion {
let question: String
let answer: Bool
let explanation: String
}
let questions: [QuizQuestion] = [
QuizQuestion(question: "Red is a four letter word", answer: false, explanation: "Red is not a four letter word"),
QuizQuestion(question: "Dog is a three letter word", answer: true, explanation: "Dog is most likely a three letter word"),
QuizQuestion(question: "Cow is a three letter word", answer: true, explanation: "Cow is most likely a three letter word")
]
var nextQuestion = QuizQuestion.self[1]
func questionVariable() {
if nextQuestion.answer == true {
questionLabel.text = nextQuestion.question
explanationLabel.text = nextQuestion.explanation
answerLabel.text = "Correct"
}
}
}
最佳答案
您可以定义一个嵌套函数(Swift 中最简单的闭包形式)，如下所示:
func getNextQuestion() -> (Int) -> QuizQuestion!
{
func incrementor(var index:Int) -> QuizQuestion! {
if index < questions.count && index >= 0 {
return questions[index]
}
else {
return nil
}
}
return incrementor
}
然后您可以访问您的问题列表，如下所示
let nextQuestion = getNextQuestion()
var question_1 = nextQuestion(0)
var question_2 = nextQuestion(1)
var question_3 = nextQuestion(2)
println("1.question text: \(question_1.question)")
println("2.question text: \(question_2.question)")
println("3.question text: \(question_3.question)")
关于arrays - 如何访问这个结构数组 - Swift，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30666021/