Question

我试图在其中创建一个包含多个数组的数组。我使用CloudKit获取数据。

import UIKit
import CloudKit

var questionsCount = 0
var questionsArray = [String]()

class hvadvilduhelstViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    //firstfield.setTitle("Klik her for at starte!", forState: .Normal)
    //secondfield.setTitle("Klik her for at starte!", forState: .Normal)
    firstfield.titleLabel?.lineBreakMode = NSLineBreakMode.ByWordWrapping
    firstfield.titleLabel?.textAlignment = NSTextAlignment.Center
    secondfield.titleLabel?.lineBreakMode = NSLineBreakMode.ByWordWrapping
    secondfield.titleLabel?.textAlignment = NSTextAlignment.Center

    let container = CKContainer.defaultContainer()
    let publicData = container.publicCloudDatabase

    let query = CKQuery(recordType: "Questions", predicate: NSPredicate(format: "TRUEPREDICATE", argumentArray: nil))
    publicData.performQuery(query, inZoneWithID: nil) { results, error in
        if error == nil { // There is no error
            for entry in results! {
                let firstOne = [entry["Question1"] as! String]
                let secondOne = firstOne + [entry["Question2"] as! String]
                let thirdOne = secondOne + [String(entry["Question1Rating"] as! Int)]
                let fourthOne = thirdOne + [String(entry["Question2Rating"] as! Int)]
                let fithOne = fourthOne + [String(entry["Reports"] as! Int)]
                questionsArray = questionsArray + fithOne
                print(questionsArray)

            }

        }
        else {
            print(error)
        }
    }

}

使用以前的代码我在控制台输出中得到这个：

["Dette er en test1", "Dette er en test2", "0", "0", "0", "test2", "test2", "0", "0", "0"]

而不是这（我想要的输出）：

[["Dette er en test1", "Dette er en test2", "0", "0", "0"], ["test2", "test2", "0", "0", "0"]]

我很简单，无法弄清楚如何做到这一点。我的计划是获取大量记录并将它们放入这个庞大的阵列中（以便于使用＆＃39;值＆＃39;）是否有更简单/更好的方法来执行此操作？

抱歉我的英语，而不是我的母语。谢谢你的帮助！

Answer 1

当你遇到这样的问题时，做一个游乐场并进行实验并做一些思考。这就是你在做什么，实质上是：

var arr = [String]()
for _ in (1...3) {
    let first = ["Mannie"]
    let second = first + ["Moe"]
    let third = second + ["Jack"]
    arr = arr + third
}
arr // ["Mannie", "Moe", "Jack", "Mannie", "Moe", "Jack", "Mannie", "Moe", "Jack"]

这不是你想要的，所以不要这样做。首先，正如你的问题标题所说，你需要一个数组数组。那么，你不想最终得到[String];你刚刚告诉我们你想要一个[[String]]（一串字符串数组）！所以首先要做出改变：

var arr = [[String]]()

现在，当您构建数组并将其插入数组数组时，请使用append方法（而不是+运算符）：

arr.append(third)

结果如下：

var arr = [[String]]()
for _ in (1...3) {
    let first = ["Mannie"]
    let second = first + ["Moe"]
    let third = second + ["Jack"]
    arr.append(third)
}
arr // [["Mannie", "Moe", "Jack"], ["Mannie", "Moe", "Jack"], ["Mannie", "Moe", "Jack"]]

现在就去做你真实的代码吧。

Answer 2

请改为尝试：

import UIKit
import CloudKit

var questionsCount = 0
var questionsArray = [[String]]()

class hvadvilduhelstViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        //firstfield.setTitle("Klik her for at starte!", forState: .Normal)
        //secondfield.setTitle("Klik her for at starte!", forState: .Normal)
        firstfield.titleLabel?.lineBreakMode = NSLineBreakMode.ByWordWrapping
        firstfield.titleLabel?.textAlignment = NSTextAlignment.Center
        secondfield.titleLabel?.lineBreakMode = NSLineBreakMode.ByWordWrapping
        secondfield.titleLabel?.textAlignment = NSTextAlignment.Center

        let container = CKContainer.defaultContainer()
        let publicData = container.publicCloudDatabase

        let query = CKQuery(recordType: "Questions", predicate: NSPredicate(format: "TRUEPREDICATE", argumentArray: nil))
        publicData.performQuery(query, inZoneWithID: nil) { results, error in
            if error == nil { // There is no error
                for entry in results! {
                    let firstOne = entry["Question1"] as! String
                    let secondOne = entry["Question2"] as! String
                    let thirdOne = String(entry["Question1Rating"] as! Int)
                    let fourthOne = String(entry["Question2Rating"] as! Int)
                    let fifthOne = String(entry["Reports"] as! Int)
                    questionsArray.append([firstOne, secondOne, thirdOne, fourthOne, fifthOne])
                    print(questionsArray)
                }
            }
            else {
                print(error)
            }
        }
    }
}

值得注意的是，questionsArray现在属于[[String]]类型，而不仅仅是[String]，而对于每个entry，您想要追加新的[String]

Swift 2 - 创建一个数组数组

2 个答案: