'(String, AnyObject)' is not convertible to '[String : AnyObject]'

Question

// response is of type AnyObject!
let responseDic = response as [String : AnyObject]
let userDic = responseDic["user"] as [String : AnyObject]

However, on the last line, I get the error:

'(String, AnyObject)' is not convertible to '[String : AnyObject]'

So I'm guessing looking up a key in a dictionary returns an optional value, so then I tried:

let userDic = responseDic["user"]? as [String : AnyObject]

But I get:

'String' is not convertible to 'DictionaryIndex<String, AnyObject>'

What's the proper way to get this to work?

Connor Pearson · Accepted Answer · 2014-07-27T15:49:43.597

13

Use an exclamation point instead to unwrap the optional:

var response: AnyObject! = ["user" : [String : AnyObject]()]
let responseDic = response as [String : AnyObject]
let userDic: [String : AnyObject] = responseDic["user"]! as [String : AnyObject]

And if you want to make sure there is a non-nil value for the key 'user' and it is a [String : AnyObject] you can use an if let:

if let user: AnyObject = responseDic["user"] {
    if let userDic = user as? [String : AnyObject]{
        //do stuff with userDic
    }
}

edited Jul 27 '14 at 15:49

answered Jul 27 '14 at 15:41

Connor Pearson

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Will this cause an exception is `responseDic["user"]` is nil? What's the safe way to do it? – Snowman Jul 27 '14 at 15:42
It will. I added another snippet – Connor Pearson Jul 27 '14 at 15:49
Is there a shorter way to do the second way you've added? – Snowman Jul 29 '14 at 16:52
you may be able to combine them into one line, although I don't think I was able to. I can't test that right now though – Connor Pearson Jul 29 '14 at 17:14

'(String, AnyObject)' is not convertible to '[String : AnyObject]'

1 Answers1