在Swift中，你可以使用JSONSerialization类将JSON字符串转换为字典。要将 Swift 字典转换为 JSON 字符串，我们可以使用JSONSerialization类的data(withJSONObject:options:)方法。这个方法将字典转换为二进制数据，然后我们可以使用String(data:encoding:)方法将其转换为字符串形式。

JSON字符串转换为字典

以下是一个例子：

// jsonStr 转为Dict
func jsonToDict() {
    print("json转为Dict")
    // 假设你有一个JSON字符串
    let jsonString = """
    {
        "name": "John Doe",
        "age": 30,
        "isDeveloper": true
    }
    """
    let jsonData = jsonString.data(using: .utf8)
    let dictData = try? JSONSerialization.jsonObject(with: jsonData!, options: []) as? [String: Any]
    print("dict data keys is:\(dictData?.keys)")
    print("dict data values is:\(dictData?.values)")
}

JSON字符串转换为数组

示例代码：

// jsonStr 转为Array
func jsonToArray() {
    print("jsonString转为数组")
    let jsonStr = """
    [
        1,
        2,
        3,
        4,
        5
    ]
    """
    let jsonData = jsonStr.data(using: .utf8)
    let arrayData = try? JSONSerialization.jsonObject(with: jsonData!, options: []) as? [Int]
    print("arrayData value is:\(arrayData)")
}

字典转为Json字符串

示例代码：

// Dict转为JsonStr
func dictToJson() {
    print("dict转为Json字符串")
    // 将字典转为JSON字符串
    let dictData = ["name": "王思聪", "city": "New York", "age": 18] as [String: Any]
    guard let jsonData = try? JSONSerialization.data(withJSONObject: dictData, options: []) else { return }
    let jsonString = String(data: jsonData, encoding: .utf8)
    print("dict转为jsonString:\(jsonString)")
}

数组转为Json字符串

示例代码：

// array转为jsonStr
func arrayToJson() {
    print("array转为Json字符串")
    let arrayData = ["name", "王思聪", "city", "New York", "age"]
    guard let jsonData = try? JSONSerialization.data(withJSONObject: arrayData, options: []) else { return }
    let jsonString = String(data: jsonData, encoding: .utf8)
    print("array转为jsonString:\(jsonString)")
}

全部的代码和效果如下：

import SwiftUI

func getFood() -> String {
    return ["🍏", "🍎", "🍐", "🍊", "🍌", "🍋", "🍉", "🍇", "🍓", "🫐"].randomElement()!
}

// json 反序列化
func jsonDecode() {
    print("json 数据解码")
    struct Person: Codable {
        let name: String
        let age: Int
        let email: String
    }
    let jsonStr = """
    {
      "name": "John",
      "age": 30,
      "email": "john@example.com"
    }
    """
    // 将json字符串转换为Data
    let jsonData = jsonStr.data(using: .utf8)
    // JSONDecoder
    let decoder = JSONDecoder()
    // 使用decoder将Data转为结构体
    let per1 = try! decoder.decode(Person.self, from: jsonData!)
    print("person name: \(per1.name)")
    print("person age: \(per1.age)")
    print("persn email: \(per1.email)")
}

// json 序列化
func jsonToStr() {
    print("json 转为字符串")
    struct Person: Codable {
        let name: String
        let age: Int
        let email: String
    }
    // 创建结构体实例
    let per2 = Person(name: "EmployA", age: 18, email: "john@example.com")
    // 创建jsonEncoder
    let jsonEncoder = JSONEncoder()
    // 将结构体实例per2转为Data
    let jsonData = try? jsonEncoder.encode(per2)
    print("jsonData: \(String(describing: jsonData))")
    // 将data转为String
    let jsonString = String(data: jsonData!, encoding: .utf8)!
    print("jsonString: \(jsonString)")
}

// jsonStr 转为Dict
func jsonToDict() {
    print("json转为Dict")
    // 假设你有一个JSON字符串
    let jsonString = """
    {
        "name": "John Doe",
        "age": 30,
        "isDeveloper": true
    }
    """
    let jsonData = jsonString.data(using: .utf8)
    let dictData = try? JSONSerialization.jsonObject(with: jsonData!, options: []) as? [String: Any]
    print("dict data keys is:\(dictData?.keys)")
    print("dict data values is:\(dictData?.values)")
}

// jsonStr 转为Array
func jsonToArray() {
    print("jsonString转为数组")
    let jsonStr = """
    [
        1,
        2,
        3,
        4,
        5
    ]
    """
    let jsonData = jsonStr.data(using: .utf8)
    let arrayData = try? JSONSerialization.jsonObject(with: jsonData!, options: []) as? [Int]
    print("arrayData value is:\(arrayData)")
}

// Dict转为JsonStr
func dictToJson() {
    print("dict转为Json字符串")
    // 将字典转为JSON字符串
    let dictData = ["name": "王思聪", "city": "New York", "age": 18] as [String: Any]
    guard let jsonData = try? JSONSerialization.data(withJSONObject: dictData, options: []) else { return }
    let jsonString = String(data: jsonData, encoding: .utf8)
    print("dict转为jsonString:\(jsonString)")
}

// array转为jsonStr
func arrayToJson() {
    print("array转为Json字符串")
    let arrayData = ["name", "王思聪", "city", "New York", "age"]
    guard let jsonData = try? JSONSerialization.data(withJSONObject: arrayData, options: []) else { return }
    let jsonString = String(data: jsonData, encoding: .utf8)
    print("array转为jsonString:\(jsonString)")
}

struct ContentView: View {
    @State var food = "🍏"

    var body: some View {
        VStack {
            Spacer()
            Spacer()
            Spacer()
            Text(food).font(.system(size: 80))
            Button(action: {
                food = getFood()
            }, label: {
                Text("今天吃啥？")
                    .padding()
                    .foregroundColor(.white)
                    .font(/*@START_MENU_TOKEN@*/ .title/*@END_MENU_TOKEN@*/)
            }).background(.orange)
                .cornerRadius(10)
            Button(action: {
                print("解码json")
                jsonDecode()
            }, label: {
                Text("解码JSON").font(/*@START_MENU_TOKEN@*/ .title/*@END_MENU_TOKEN@*/).foregroundColor(.white).padding()
            }).background(.pink).cornerRadius(10)
            Button(action: {
                jsonToStr()
            }, label: {
                Text("编码JSON").font(/*@START_MENU_TOKEN@*/ .title/*@END_MENU_TOKEN@*/).foregroundColor(.white).padding()
            }).background(.blue).cornerRadius(10)
            Button(action: {
                print("json转为dict类型")
                jsonToDict()
            }, label: {
                Text("Json转Dict").foregroundColor(.white).padding(10).font(/*@START_MENU_TOKEN@*/ .title/*@END_MENU_TOKEN@*/)
            }).background(.yellow).cornerRadius(10)
            Button(action: {
                print("json转为数组")
                jsonToArray()
            }, label: {
                Text("Json转Array").font(/*@START_MENU_TOKEN@*/ .title/*@END_MENU_TOKEN@*/).padding(10).foregroundColor(.white)
            }).background(.gray).cornerRadius(10)
            Button(action: {
                print("dict数据转为json")
                dictToJson()
            }, label: {
                Text("Dict转为Json").foregroundColor(.white).padding(10).font(/*@START_MENU_TOKEN@*/ .title/*@END_MENU_TOKEN@*/)
            }).background(.green).cornerRadius(10)
            Button(action: {
                print("字典转为数组")
                arrayToJson()
            }, label: {
                Text("Dict转数组").font(/*@START_MENU_TOKEN@*/ .title/*@END_MENU_TOKEN@*/).foregroundColor(.white).padding(10)
            }).background(.purple).cornerRadius(10)
            Spacer()
            Spacer()
            Spacer()
        }
    }
}