在swift中检查数组元素

目前正在为我的应用程序实现一个基于引号的collectionsfunction。 我想检查用户是否已将元素保存到数组中。 如果他们有，我会更改一个帮助按钮以不喜欢按钮。
导入UIKit

class DreamViewController: UIViewController { @IBOutlet var liketext: UIButton! @IBOutlet var QuoteImage: UIImageView! @IBOutlet weak var DreamLabel: UILabel! var counter = 1 var factIndex = 0 let dreamFact = Dream() override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. DreamLabel.text = dreamFact.dreamArray[factIndex] } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } @IBAction func LeftSwipe() { factIndex-- var number = dreamFact.dreamArray.count - 1 if (factIndex = dreamFact.dreamArray.count { self.factIndex = 0 } DreamLabel.text = dreamFact.dreamArray[factIndex] if counter == 36 { counter = 1 } else { self.counter++ } QuoteImage.image = UIImage(named: "frame\(counter).jpg") } struct Constants { static let defaults = NSUserDefaults.standardUserDefaults() static let fqKey = "FavoriteQuotes" static let like = "Like" static let unlike = "Unlike" } class DreamViewController { var favouriteQuotesArray = Constants.defaults.objectForKey(Constants.fqKey) as? [String] ?? [String]() { didSet { Constants.defaults.setObject(favouriteQuotesArray, forKey: Constants.fqKey) } } @IBOutlet weak var likeButton: UIButton! { didSet { let favourite = dreamArray[factIndex] if let foundIndex = find(favouriteQuotesArray, favourite) { likeButton.setTitle(Constants.unlike, forState: .Normal) } else { likeButton.setTitle(Constants.like, forState: .Normal) } } } @IBAction func likeButtonClicked(sender: UIButton) { } } } 

对文本的依赖是不可靠的，因为如果用户重新打开应用程序，该元素仍然会被保存，而不是以默认值开始 。 如果在数组中找到该元素。 如果元素存在，我将如何在我的favouriteQuotesArray中执行搜索 ：

 if elementfound statement { button.settitle(unlike) removearrayatindex statement. } else { button.settitle(like) makeQuoteFavourite() } 

数组检查语句如何？ PS如果可以，请提供有关构建删除类的提示？ 更新：

  var favouriteQuotesArray: [String] = NSUserDefaults.standardUserDefaults().objectForKey("thekey") as! [String] func makeQuoteFavourite() { if favouriteQuotesArray == nil { favouriteQuotesArray = [] } let currentQuote = dreamFact.dreamArray[factIndex] favouriteQuotesArray.append(currentQuote) NSUserDefaults.standardUserDefaults().setObject(favouriteQuotesArray, forKey: "thekey") } @IBAction func likeButton() { if contains(favouriteQuotesArray, dreamFact.dreamArray[factIndex]) { liketext.setTitle("Unlike", forState: UIControlState.Normal) } 

Answer 1

这样做吧; 一些清洁编码技术，以切断瓦砾包括在内。

favouriteQuotesArray的宣言是金星的一个class轮。 知道了吗？

 import UIKit struct Constants { static let defaults = NSUserDefaults.standardUserDefaults() static let fqKey = "FavoriteQuotes" static let like = "Like" static let unlike = "Unlike" } class Page2ViewController: UIViewController { var dreamArray = [String]() // place holder so class compiles var factIndex = 0 // place holder so class compiles var favouriteQuotesArray = Constants.defaults.objectForKey(Constants.fqKey) as? [String] ?? [String]() { didSet { Constants.defaults.setObject(favouriteQuotesArray, forKey: Constants.fqKey) } } @IBOutlet weak var likeButton: UIButton! { didSet { let favourite = dreamArray[factIndex] if let foundIndex = find(favouriteQuotesArray, favourite) { likeButton.setTitle(Constants.unlike, forState: .Normal) } else { likeButton.setTitle(Constants.like, forState: .Normal) } } } @IBAction func likeButtonClicked(sender: UIButton) { let favourite = dreamArray[factIndex] if let foundIndex = find(favouriteQuotesArray, favourite) { sender.setTitle(Constants.like, forState: .Normal) favouriteQuotesArray.removeAtIndex(foundIndex) } else { sender.setTitle(Constants.unlike, forState: .Normal) favouriteQuotesArray.append(favourite) } } } 

Answer 2

尝试这个：

 let currentQuote = dreamFact.dreamArray[factIndex] if find(favouriteQuotesArray!, currentQuote) != nil { //Do something } 

Answer 3

找出数组中元素的更好，更快捷的方法是：

 if contains(yourFavArray, stringStatement){ //Contains you can write your logic } 

更改您的favouriteArray如下：

 var favouriteQuotesArray: [String] = NSUserDefaults.standardUserDefaults().objectForKey("thekey") as! [String] 

编辑：

  if let foundIndex = find(favouriteQuotesArray, dreamFact.dreamArray[factIndex]) { sender.setTitle(Constants.like, forState: .Normal) favouriteQuotesArray.removeAtIndex(foundIndex) }