循环遍历 JSON 对象 Swift 5答案

【问题标题】：Loop through JSON Object Swift 5循环遍历 JSON 对象 Swift 5
【发布时间】：2021-06-16 11:21:11
【问题描述】：

我正在尝试遍历 JSON 对象并获取 swift 编程语言中的特定值。

我收到了这样的 JSON

let json = try? JSONSerialization.jsonObject(with: data, options: []) as? [String : Any],
let charges = json["charges"] as? [String:Any]

json:

{
  object: 'list',
  data: [
    {
      id: 'ch_1IWQEfKn7R1M6tqnhrpyIhMk',
      object: 'charge',
      amount: 555,
      amount_captured: 555,
      amount_refunded: 0,
      application: 'ca_IXRQuoBh5mSJXXpEccXssma6Oz0u3HjX',
      application_fee: 'fee_1IWQEfKn7R1M6tqnvTHQeSEF',
      application_fee_amount: 6,
      balance_transaction: 'txn_1IWQEfKn7R1M6tqnkK9LCNuM',
      billing_details: [Object],
      calculated_statement_descriptor: 'TEST ACCOUNT',
      captured: true,
      created: 1616090777,
      currency: 'usd',
      customer: null,
      description: null,
      destination: null,
      dispute: null,
      disputed: false,
      failure_code: null,
      failure_message: null,
      fraud_details: {},
      invoice: null,
      livemode: false,
      metadata: {},
      on_behalf_of: null,
      order: null,
      outcome: [Object],
      paid: true,
      payment_intent: 'pi_1IWQEeKn7R1M6tqnYbGfFCzg',
      payment_method: 'pm_1IWQEeKn7R1M6tqnKLxSg6vZ',
      payment_method_details: [Object],
      receipt_email: null,
      receipt_number: null,
      receipt_url: 'https://pay.stripe.com/receipts/acct_1ISouBKn7R1M6tqn/ch_1IWQEfKn7R1M6tqnhrpyIhMk/rcpt_J8hdy05N6VfOmRECdumpti8Jiljz2Et',
      refunded: false,
      refunds: [Object],
      review: null,
      shipping: null,
      source: null,
      source_transfer: null,
      statement_descriptor: null,
      statement_descriptor_suffix: null,
      status: 'succeeded',
      transfer_data: null,
      transfer_group: null
    },
    {
      id: 'ch_1IU62QKn7R1M6tqnbXXlOpch',
      object: 'charge',
      amount: 5599,
      amount_captured: 5599,
      amount_refunded: 0,
      application: 'ca_IXRQuoBh5mSJXXpEccXssma6Oz0u3HjX',
      application_fee: 'fee_1IU62RKn7R1M6tqnLle3zblA',
      application_fee_amount: 56,
      balance_transaction: 'txn_1IU62RKn7R1M6tqn3ttu9F3N',
      billing_details: [Object],
      calculated_statement_descriptor: 'TEST ACCOUNT',
      captured: true,
      created: 1615536482,
      currency: 'usd',
      customer: null,
      description: null,
      destination: null,
      dispute: null,
      disputed: false,
      failure_code: null,
      failure_message: null,
      fraud_details: {},
      invoice: null,
      livemode: false,
      metadata: {},
      on_behalf_of: null,
      order: null,
      outcome: [Object],
      paid: true,
      payment_intent: 'pi_1IU62NKn7R1M6tqnWSOLJVge',
      payment_method: 'pm_1IU62PKn7R1M6tqnIyOUgUMX',
      payment_method_details: [Object],
      receipt_email: null,
      receipt_number: null,
      receipt_url: 'https://pay.stripe.com/receipts/acct_1ISouBKn7R1M6tqn/ch_1IU62QKn7R1M6tqnbXXlOpch/rcpt_J6Id30gjIhQU6AWPBHgUXoujbhFOTyf',
      refunded: false,
      refunds: [Object],
      review: null,
      shipping: null,
      source: null,
      source_transfer: null,
      statement_descriptor: null,
      statement_descriptor_suffix: null,
      status: 'succeeded',
      transfer_data: null,
      transfer_group: null
    },
    {
      id: 'ch_1IU60cKn7R1M6tqny9o2NV5W',
      object: 'charge',
      amount: 1000,
      amount_captured: 1000,
      amount_refunded: 0,
      application: 'ca_IXRQuoBh5mSJXXpEccXssma6Oz0u3HjX',
      application_fee: 'fee_1IU60cKn7R1M6tqn95nUHETe',
      application_fee_amount: 10,
      balance_transaction: 'txn_1IU60cKn7R1M6tqnZKNbSEXf',
      billing_details: [Object],
      calculated_statement_descriptor: 'TEST ACCOUNT',
      captured: true,
      created: 1615536370,
      currency: 'usd',
      customer: null,
      description: null,
      destination: null,
      dispute: null,
      disputed: false,
      failure_code: null,
      failure_message: null,
      fraud_details: {},
      invoice: null,
      livemode: false,
      metadata: {},
      on_behalf_of: null,
      order: null,
      outcome: [Object],
      paid: true,
      payment_intent: 'pi_1IU60ZKn7R1M6tqnrUSK1TQD',
      payment_method: 'pm_1IU60bKn7R1M6tqnAUHQXqJG',
      payment_method_details: [Object],
      receipt_email: null,
      receipt_number: null,
      receipt_url: 'https://pay.stripe.com/receipts/acct_1ISouBKn7R1M6tqn/ch_1IU60cKn7R1M6tqny9o2NV5W/rcpt_J6Ib5PEZQzEgyXWoOwKcxZ9x7mByCVu',
      refunded: false,
      refunds: [Object],
      review: null,
      shipping: null,
      source: null,
      source_transfer: null,
      statement_descriptor: null,
      statement_descriptor_suffix: null,
      status: 'succeeded',
      transfer_data: null,
      transfer_group: null
    }
  ],
  has_more: true,
  url: '/v1/charges'
}

如何遍历 JSON 对象以接收“金额”、“货币”和“id”。

例如 PSUEDO：

for item in charges {
    print(item["amount"])
    print(item["currency"])
    print(item["id"])
}

我可能不正确地初始化 json，例如

json["charges"] 为？ [字符串：任何]

【问题讨论】：

JSON 似乎不正确。发布正确的 JSON。
@Harish 我已经更新了 json 对象
第一点，不要使用try ?。使用do/try/catch，这样您就可以报告错误，而不是简单地丢弃它们。第 2 点，为您的数据创建适当的结构并使用 Codable 和 JSONDecoder 而不是 JSONSerialization。

标签： ios json swift swift5

【解决方案1】：

您不应该使用try ? - 这会抛出错误。始终使用do/try/catch 以便处理发生的任何错误，即使您只是打印它们。

JSONSerialization 并将 JSON 解码为数组和字典并不是最佳实践。最好创建符合Codable 的合适结构并使用JSONDecoder。

struct Response: Codable {
    var object: String
    var hasMore: Bool
    var data: [ResponseData]
    var url: String

    enum CodingKeys: String, CodingKey {
        case object
        case hasMore = "has_more"
        case url
        case data
    }
}

struct ResponseData: Codable {
    var amount: Int
    var currency: String
    var id: String
}

为简单起见，我没有将所有属性添加到 ResponseData 结构中，只是您说您感兴趣的那些

do {
   let json = try JSONDecoder().decode(Response.self, from: data)
   json.data.forEach { charge in
      print(charge.id)
      print(charge.currency)
      print(charge.ammount)
   }
} catch {
   print("Error! \(error)")
}

【讨论】：