ios - Alamofire with append won't show data -

i want append data in code here below. gives me empty array why? because used framework?

class func getdatabyjson() -> array<string> {      let urldb = "https://dl.dropboxusercontent.com/u/13259946/voorbeeld.json"      //werkt!      var data: array<string> = []      alamofire.request(.get, urldb)         .responsejson { (request, response, json, error) in             //println(error)              if let groups : anyobject! = json {                  var group = groups["groups"] nsarray                  g in group {                     data.append(g["name"] nsstring)                     //println(data)                 }                 //println(data)             }            println(data)         //return data     }     return data } 

alamofire asynchronously. instead of having getdatabyjson return array of strings, have accept additional completionhandler parameter executes response data when request finishes.