Alamofire can't access keys of json response

问题:

I'm new to using Alamofire and have encountered an issue. I'm able to run the following code to print out all the data from an API endpoint.

Alamofire.request("http://codewithchris.com/code/afsample.json").responseJSON { response in
    if let JSON = response.result.value {
        print(JSON)
    }
}

The issue is that when I run this:

Alamofire.request("http://codewithchris.com/code/afsample.json").responseJSON { response in
    if let JSON = response.result.value {
        print(JSON["firstkey"])
    }
}

I get the error:

Type 'Any' has no subscript members

I don't know why this error is happening, it seems as if I'm accessing the data correctly. Any help would be great, thanks!

I have tried formatting it using both:

print(JSON["firstkey"] as String)

and

print(JSON["firstkey"] as [String:Any]

but they still give the same error.

This is the JSON on my endpoint:

{
    "firstkey":"it worked!",
    "secondkey":["item1", "item2", "item3"]
}

回答1:

This is really simple. You just need to force cast (as!) your JSON. so change your code to this and it will work:

Alamofire.request("http://codewithchris.com/code/afsample.json").responseJSON { response in
    if let JSON = response.result.value {
        let json = JSON as! [String: Any]
        print(json["firstkey"])
    }
}

Edit 1: As you said in comments that you are using SwiftyJSON package. Sample code is as follows:

Alamofire.request("http://codewithchris.com/code/afsample.json").responseJSON { response in
        if let value = response.result.value {
            let json = JSON(value)
            print(json["firstkey"].stringValue)
        }
    }

Alamofire.request("https://mmcalc.com/api").responseJSON { response in
        if let value = response.result.value {
            let json = JSON(value)
            print(json.arrayValue[0]["uniqueUsers"].stringValue)
        }
    }

回答2:

You are trying to get the value with getting the object, try this:

Alamofire.request("http://codewithchris.com/code/afsample.json").responseJSON { response in
if let result = response.result.value {
    let JSON = result as! NSDictionary
    print(JSON["firstkey"])
}
}

Hope it will work!

回答3:

You should add ! at the end of code before ) to force unwrap the value

   Alamofire.request("http://codewithchris.com/code/afsample.json").responseJSON { response in
      if let JSON = response.result.value {
      let json = JSON as! [String: Any]
      print(json["firstkey"]!)
   }
}