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标题: ios - 快速迭代数组时出错 [打印本页]

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作者: 菜鸟教程小白    时间: 2022-12-12 14:24
标题: ios - 快速迭代数组时出错

我正在尝试遍历数组并获取坐标，但它给了我一个错误，我无法访问我的数组。数据通过一个序列传递，如果我打印它表明它正在工作，因此数据可以正确传输，但无法弄清楚为什么我不能遍历数组并提取纬度和经度。

这是控制台的输出。

DeliveryDestinations(NameOrBusiness: Optional("In-N-Out Burger"), FirstLineAddress: Optional("550 Newhall Dr"), SecondLineAddress: Optional(" United States"), CityLineAddress: Optional(" San Jose"), PostcodeLineAddress: Optional(" CA 95110"), DistanceToDestination: Optional(9.2807823200000001), Lat: Optional(37.350253606833043), Long: Optional(-121.92182779312132))

import UIKit
import MapKit
import CoreLocation

class DeliveryLocationsVC: UIViewController {

    @IBOutlet weak var mapView: MKMapView!

    var addressArr = [DeliveryDestinations]()


    override func viewDidLoad() {
        super.viewDidLoad()

        print(addressArr)


navigationItem.title = "Delivery Location"
        // Do any additional setup after loading the view.

        for (theKey, theValue) in addressArr { //<-- error can't access the elements in array
            if (theKey == "Lat") {
                if let coordinateseliveryDestinations = theValue {
                print (coordinates)
            }
            print("Item \(theKey): \(theValue)")
            }
        }
    }
}

我的数组来自下面的结构

import Foundation
import MapKit

struct DeliveryDestinations {
    var NameOrBusiness: String?
    var FirstLineAddress: String?
    var SecondLineAddress: String?
    var CityLineAddress: String?
    var PostcodeLineAddress: String?
    var DistanceToDestination: CLLocationDistance?
    var Lat: Double?
    var Long: Double?


    init(NameOrBusiness: String?, FirstLineAddress: String?, SecondLineAddress: String?, CityLineAddress: String?, PostCodeLineAddress: String?, DistanceToDestination: CLLocationDistance?, Lat: Double?, Long: Double? ) {
        self.NameOrBusiness = NameOrBusiness
        self.FirstLineAddress = FirstLineAddress
        self.SecondLineAddress = SecondLineAddress
        self.CityLineAddress = CityLineAddress
        self.PostcodeLineAddress = PostCodeLineAddress
        self.DistanceToDestination = DistanceToDestination
        self.Lat = Lat
        self.Long = Long

    }

}

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Best Answer-推荐答案

你有一个数组(而不是字典)，所以你需要做的是像这样迭代:

for object in addressArr {
    ...
    // get coordinates from object
    let lat = object.Lat
    let long = object.Long
}

或者，如果您还需要表格行的索引，您可以这样做:

for (i, object) in addressArr.enumerated() {
    ...
    // get coordinates from object
    let lat = object.Lat
    let long = object.Long
    print ("Destination at index \(i) has coordinate: (\(lat), \(long))")
}

我怎么知道它是一个数组？

代码中的符号

 var addressArr = [DeliveryDestinations]()

总是意味着，这是一个DeliveryDestinations对象数组。 当您将其打印出来时，您会打印出数组中的对象。 在你的情况下，这个对象有一个“像字典一样”的描述，所以 print 函数像这样打印它。

在每个对象中，使用 description 函数，您可以指定在对象(或这些对象的数组)上打印时文本的外观

关于ios - 快速迭代数组时出错，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47994547/

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