Swift中的嵌套類

Question

我遇到了swift問題。

我有city.swift文件2類是這樣的：

import Foundation 

class Place { 
    var name : String! 
    var tel : String! 
    var kind : String! 
} 

class City { 
    var name : String! 
    var describe : String! 

    var hotel : Place! 

    init(data: NSDictionary) 
    { 
     self.name = data["name"] as? String 
     self.describe = data["city_description"] as? String 
     self.hotel = data["hotelName"] as? Place 
    } 
} 

我從JSON文件解析的信息。 我的問題是，當我試圖讓cities.hotel與此代碼：

if let items = json["cities"] as? NSArray { 
     for item in items { 
       let place = Place() 
       let cities = City(data: item as! NSDictionary) 
        println("\(cities.hotel)") 
       } 
     } 

Xcode的還給我「無」，但city.name和city.describe做工精細。爲什麼？ 感謝您的幫助。

編輯： 這是我的OBJ-C代碼和精細工作：

City.h

@property (nonatomic, retain) NSString *name; 
@property (nonatomic, retain) NSString *describe; 
@property (nonatomic, retain) Place *hotel; 

Place.h

@property (retain,nonatomic) NSString *name; 
@property (retain,nonatomic) NSString *address; 
@property (retain,nonatomic) NSString *tel; 

collectionView.m

_jsonData = [NSJSONSerialization JSONObjectWithData:fileData options:kNilOptions error:&error]; 
_citiesListArray = [_jsonData objectForKey:@"cities"]; 

_citySingleList = [[NSMutableArray alloc] init]; 

for (NSDictionary *cityDictionary in _citiesListArray) { 

    City *city = [[City alloc] init]; 

    city.name = [cityDictionary objectForKey:@"name"]; 
    city.describe = [cityDictionary objectForKey:@"city_description"]; 

    city.hotel = [cityDictionary objectForKey:@"hotels"]; 

    NSLog(@"%@", city.hotel); 

} 

和JSON文件

"cities": [ 
    { 
     "name": "City Name", 
     "city_description" : "City Describe", 
     "hotels": [ 
      { 
       "name" : "Hotel Name", 
       "tel" : "Hotel Tel", 
      }, 
     ] 
    } 
] 

，當我的NSLog在city.hotel OBJ-C還給我

{ 
    "name" : "Hotel Name", 
    "tel" : "Hotel Tel", 
}, 

但我的銀行代碼回零，我哪裏出錯？再次感謝您的幫助

P.S酒店屬性是Place類的一個子類。因爲我想稍後使用它：

city.hotel.name = hotelDictionery["name"] 

Answer 1

正如我在評論中已經說過的，您並未解析酒店。所以，這裏是你可以放入一個遊樂場和驗證自己

需要的Xcode 7和斯威夫特2

//: Playground - noun: a place where people can play 

import UIKit 

// This is a Dictionary representation of your JSON for a single element 
let item: [String : AnyObject] = [ 
    "name" : "City Name", 
    "city_description" : "City Describe", 
    "hotels": [ 
     "name" : "Hotel Name", 
     "tel" : "Hotel Tel", 
    ] 
] 

// Here is your Place value as a strict, which is the way I would write it 

struct Place { 
    let name: String 
    let tel: String 
    let kind: String 
} 

// Put custom initialisers in an extension. That way, the default initialiser is provided by the system 
extension Place { 
    // The initialiser takes a dictionary that gets the values from the dictionary, 
    // filling in missing values with empty strings 
    init(dictionary: [String : AnyObject]) { 
     self.name = dictionary["name"] as? String ?? "" 
     self.tel = dictionary["tel"] as? String ?? "" 
     self.kind = dictionary["kind"] as? String ?? "" 
    } 
} 

// Here is your City value as a struct, which is the way I would write it 

struct City { 
    let name: String 
    let describe: String 
    let hotel: Place 

} 

extension City { 
    // The initialiser takes a dictionary that gets the values from the item dictionary, 
    // missing values are provided as empty strings 
    init(dictionary: [String: AnyObject]) { 
     self.name = dictionary["name"] as? String ?? "" 
     self.describe = dictionary["city_description"] as? String ?? "" 

     if let hotels = dictionary["hotels"] as? [String : AnyObject] { 
      self.hotel = Place(dictionary: hotels) 
     } else { 
      self.hotel = Place(name: "Default name", tel: "Default tel", kind: "Default kind") 
     } 
    } 
} 

// Now parse the item 

let city = City(dictionary: item) 

對我來說一個完整的例子，這給輸出：