使用未解決的indetifier jsonResult

Question

我每次嘗試修復它都會收到此錯誤。請幫助

do { 
    if let jsonResult = try JSONSerialization.jsonObject(with: data, options: []) as? [String:AnyObject] { 
     print(jsonResult) 
    } 
} catch let error as NSError { 
    print(error.localizedDescription) 
} 

if (jsonResult != nil) { 
    print(jsonResult) 
} else { 
    // couldn't load JSON, look at error 
} 

Answer 1

jsonResult在其創建的DO-try-catch語句外使用，所以這就是爲什麼你不能訪問它。這裏是更正的代碼：

do { 
    if let jsonResult = try JSONSerialization.jsonObject(with: data, options: []) as? [String:AnyObject] { 
     print(jsonResult) 
     //The following lines of code is commented out because you have used if let outside to make sure that jsonResult here is not nil. 
     //So you do not need to check for it again 
     //if (jsonResult != nil) { 
     // print(jsonResult) 
     //} else { 
     // // couldn't load JSON, look at error 
     //} 
    } 

} catch let error as NSError { 
    print(error.localizedDescription) 
}