DispatchQueue

DispatchQueue.swift

// ตัวอย่างการทำงานของ Task
var ID:string = nil

func getDataFromURL() {
  let URL:string = "https://xxx...."
  Alamofire.request(URL, method: .get, parameters: nil).responseJSON { response in
      let dataJSON = JSON(response.result.value!)
        if let id:String = dataJSON["data"]["id"].string {
            self.ID = id
        }          
   }
	
		self.checkData()
}

func checkData() {
  if self.ID == nil {
    print("ID = Nil")
  } else { 
    print("ID != Nil")
  }
}

// Run Function
self.getDataFromURL() //OUTPUT = ID = Nil