如何迭代具有嵌套字典的字典数组？

Question

我有JSON

http://maps.googleapis.com/maps/api/directions/json?&origin=28.594517,77.049112&destination=28.654109,77.34395&travelMode=DRIVING&provideRouteAlternatives=false&sensor=false

我想访问距离中所有的值，这是逐步的。

这是我的代码

class Router {
var getValue = Double()

func downloadData(complete: downloadComplete) {

    let currentURL = URL(string:getURL)!
    Alamofire.request(currentURL).responseJSON { (responseJSON) in
        let result = responseJSON
        //            print(result)

        if let dict = result.value as? Dictionary<String,AnyObject>{

            if let routes = dict["routes"] as? [Dictionary<String, AnyObject>]{

                if let legs = routes[0]["legs"] as? [Dictionary<String, AnyObject>]{

                    if let steps = legs[0]["steps"] as? [Dictionary<String, AnyObject>]{

                        for index in steps{
                            if let distance = steps["distance"] as? Dictionary<String,AnyObject>{
                                if let value = distance["value"] as? Double{
                                    self.getValue = self.getValue + value
                                    print(self.getValue)
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    complete()

}

我在以下方面遇到错误：

if let distance = steps["distance"] as? Dictionary<String,AnyObject>{

其中说：

无法用字符串类型的索引下标“ [字典]”类型的值

我该如何访问？

Answer 1

您正在尝试通过键访问字典数组的值。 您应该将steps["distance"]更改为index["distance"] 。

if let distance = index["distance"] as? Dictionary<String,AnyObject>{
    if let value = distance["value"] as? Double{
        self.getValue = self.getValue + value
        print(self.getValue)
    }
}

Answer 2

错误很明显。 steps [“ distance”]是字典的数组，可以像step [0]，steps [1]一样访问。 您需要更改以下行

if let distance = steps["distance"] as? Dictionary<String,AnyObject>

至

if let distance = index["distance"] as? Dictionary<String,AnyObject>