- // response is of type AnyObject!
- let responseDic = response as [String : AnyObject]
- let userDic = responseDic["user"] as [String : AnyObject]
但是,在最后一行,我得到错误：
- '(String,AnyObject)' is not convertible to '[String : AnyObject]'
所以我猜想在字典中查找一个键可以返回一个可选的值,所以我试过：
- let userDic = responseDic["user"]? as [String : AnyObject]
但我得到：
- 'String' is not convertible to 'DictionaryIndex<String,AnyObject>'
什么是正确的方式让这个工作？
使用感叹号来解开可选项：
- var response: AnyObject! = ["user" : [String : AnyObject]()]
- let responseDic = response as [String : AnyObject]
- let userDic: [String : AnyObject] = responseDic["user"]! as [String : AnyObject]
如果你想确定key’user’是一个非零值,它是一个[String：AnyObject],你可以使用一个if：
- if let user: AnyObject = responseDic["user"] {
- if let userDic = user as? [String : AnyObject]{
- //do stuff with userDic
- }
- }
