在 Swift 5 中從數組創建字典

Question

我需要為數組的第一個索引創建一個自定義類型的數組字典。

樣本數組：["ABC","ZYZ","123"]

所需結果：[{"name" : "ABC", "type:"A"},{"name" : "ZYZ", "type:"B"},{"name" : "123", "type: “乙”}]

注意第一個索引的類型 A。

我的代碼

for url in urlArray {
        urlDict["name"] = url
    }

Answer 1

我想您可以使用高階函數，例如map或reduce

這是一個使用reduce的例子

var array = ["ABC","ZYZ","123"]

var result = array.reduce([[String: String]](), { (previous, current) -> [[String: String]] in
    let type = previous.count == 0 ? "A" : "B"
    let dictForCurrent = [
        "name": current,
        "type": type
    ]
    return previous + [dictForCurrent]
})

print(result)

結果：

[["type": "A", "name": "ABC"], ["type": "B", "name": "ZYZ"], ["name": "123", "type": “乙”]]

Answer 2

您可以做一個map ，然后單獨更改第一個字典的類型：

var dicts = urlArray.map { ["name": $0, "type": "B"] }
dicts[0]["type"] = "A"

---

看到您所有的字典鍵都是一樣的，並且您將其發送到服務器， Codable結構可能是更好的選擇。

struct NameThisProperly : Codable {
    var name: String
    var type: String
}

var result = urlArray.map { NameThisProperly(name: $0, type: "B") }
result[0].type = "A"
do {
    let data = try JSONDecoder().encode(result)
    // you can now send this data to server
} catch let error {
    ...
}

Answer 3

使用map(_:)將array每個元素轉換為dictionary如下所示，

let arr = ["ABC","ZYZ","123"]
let result = arr.map { (element) -> [String:String] in
    var dict = [String:String]()
    dict["name"] = element
    if let char = element.first {
        dict["type"] = String(char)
    }
    return dict
}

print(result)

Answer 4

使用reduce將數組轉換為字典：

let resultDict: [String: String]
      = array.reduce(into: [:]) { dict, url in
        dict["name"] = url
      }

結果將如下所示：

[
  "name": URL1,
  "name": URL2
]

Answer 5

由於您擔心索引，我的方法將使用enumerated()給出索引

   let array = ["ABC","ZYZ","123"]
   var results: [[String: String]] = []
   for (i, content) in array.enumerated() {
      let type: String = i == 0 ? "A" : "B"
      results.append(["name": content, "type": type])
    }
    print(result)

// [["type": "A", "name": "ABC"], ["name": "ZYZ", "type": "B"], ["type": "B", "name": "123"]]