Swift 中对象的自动 JSON 序列化和反序列化

在Swift中，我们经常需要将对象转换为JSON格式，或者将JSON格式的数据转换为对象。为了简化这个过程，Swift提供了自动的JSON序列化和反序列化功能。这使得我们可以轻松地在Swift中进行对象的存储和传输。

swift
struct Person: Codable {
    var name: String
    var age: Int
}
let person = Person(name: "John", age: 30)
let encoder = JSONEncoder()
if let jsonData = try? encoder.encode(person) {
    if let jsonString = String(data: jsonData, encoding: .utf8) {
        print(jsonString)
        // 输出：{"name":"John","age":30}
    }
}

swift
let jsonString = "{\"name\":\"John\",\"age\":30}"
let decoder = JSONDecoder()
if let jsonData = jsonString.data(using: .utf8) {
    if let person = try? decoder.decode(Person.self, from: jsonData) {
        print(person)
        // 输出：Person(name: "John", age: 30)
    }
}

swift
struct Person: Codable {
    var name: String
    var age: Int
    
    enum CodingKeys: String, CodingKey {
        case name = "personName"
        case age = "personAge"
    }
}
let person = Person(name: "John", age: 30)
let encoder = JSONEncoder()
encoder.keyEncodingStrategy = .convertToSnakeCase
if let jsonData = try? encoder.encode(person) {
    if let jsonString = String(data: jsonData, encoding: .utf8) {
        print(jsonString)
        // 输出：{"person_name":"John","person_age":30}
    }
}