哪个是在swift中创建json对象的最佳方式？

Question

我试图用字典在swift中创建json对象，但代码变得越来越长。有没有办法减少例如这段代码的行数？你可以看到，两个字典是一样的，除了“id”字段 如果有可能，而无需使用外部库

var product: [String: String] = [ 
      "chemical_id":String(activity.chemical!.id), 
      "plague_id":String(activity.plague!.id), 
      "justification":activity.justification!, 
      "amount":activity.amount!, 
      "amount_scope":activity.amount_scope!, 
      "security_time":activity.security_time!, 
      "effectiveness": activity.effectiveness! 
     ] 
     if activity.id != -1 { 
      product = [ 
       "id":String(activity.id), 
       "chemical_id":String(activity.chemical!.id), 
       "plague_id":String(activity.plague!.id), 
       "justification":activity.justification!, 
       "amount":activity.amount!, 
       "amount_scope":activity.amount_scope!, 
       "security_time":activity.security_time!, 
       "effectiveness": activity.effectiveness! 
      ] 
     } 

Answer 1

只需添加它的条件

if activity.id != -1 { 
    product["id"] = String(activity.id) 
}