ios - error using valueForKey in swift -

why error when used valueforkey... using same trick in objectivec ...

in objectivec, code

self.strsubscribe =[responseobject[@"subscribe"] valueforkey:@"subscribe_ids"];  

in swift , code

self.strsubscribe = responseobject["subscribe"].valueforkey["subscribe_ids"] as! string   

i declare variables

var arraysubcategory : nsmutablearray! = nsmutablearray() var strsubscribe:string!   

and tried access value below response

 {       subscribe =              {                "subscribe_ids" = "1,14";             }   } 

edit works using amit , eric's solution following data

 {       data =     (             {         "subscribe_ids" = "1,14";     }     );  }      let dictionary = responseobject["data"][0] as! dictionary<string,anyobject>   self.strsubscribe = dictionary["subscribe_ids"] as! string   

or//

 if let dic = responseobject["data"][0] as? [string:string], let ids = dic["subscribe_ids"] { self.strsubscribe = ids   } 

but gives me error:

could not find member 'subscript'

swift doesn't know type of responseobject["subscribe"], have compiler bit; example:

if let dic = responseobject["subscribe"] as? [string:string], let ids = dic["subscribe_ids"] {     self.strsubscribe = ids  // "1,14" } 

update:

it's still same problem: compiler doesn't know type of responseobject["data"], when try access subscript there's error (because you know it's dictionary inside array, compiler doesn't).

one solution give type compiler declaring array of dictionaries in if let condition:

if let arr = responseobject["data"] as? [[string:string]], let ids = arr[0]["subscribe_ids"] {     self.strsubscribe = ids   } 

notice it's [[string:string]] (array of dictionaries), not [string:string] (dictionary).