Swift Codable，数组值作为键

Posted 2023-03-15

【中文标题】Swift Codable，数组值作为键

【英文标题】：Swift Codable, array value as key

【发布时间】：2018-11-05 20:31:17

【问题描述】：

这是我的 JSON：

 "items": [
    "name": "Item 1",
    "description": "This is Item 1",
    "categories": ["Category1", "Category2", "Category3", "Category4"],
    "size": ["M", "L"]
 ,
    "name": "Item 2",
    "description": "This is Item 2",
    "categories": ["Category1", "Category3", "Category4"],
    "size": ["M"]
 ]

我可以很好地阅读和打印它

但是，我想将此结构更改为这样的结构，其中每个项目按类别和大小分隔，并且类别用作键。

 "categories": 
  "category1": [
   "name": "Item 1",
   "description": "This is Item 1",
   "size": "M"
,
   "name": "Item 1",
   "description": "This is Item 1",
   "size": "L"
,
   "name": "Item 2",
   "description": "This is Item 2",
   "size": "M"
...],
 "category2": [
  ...
]

我已经创建了以下数据结构，但我不太确定如何继续：

struct Categories: Codable 
 let category: String
 let items: [Item]

 struct Item: Codable 
  let name, description, size: String
 

Codable 是解决这个问题的正确方法吗？如果是这样的话;我将如何继续实现这一目标？

【问题讨论】：

为什么要更改 JSON 以包含这么多重复数据？

【参考方案1】：

对于你当前需要的 json

struct Root: Codable 
    let categories: [String:[Item]]


struct Item: Codable 
    let name, description, size: String

不过我觉得还是这样比较好

    "category1": [
       "name": "Item 1",
       "description": "This is Item 1",
       "size": "M"
       ,
       "name": "Item 1",
       "description": "This is Item 1",
       "size": "L"
       ,
       "name": "Item 2",
       "description": "This is Item 2",
       "size": "M"
    ],
    "category2": [

    ]

这会让你这样做

let res = try? JSONDecoder().decode([String:[Item]].self,from:jsonData)

没有Root 结构和无用的categories 键