ios - Firebase DB Key, Name, Value clarification -

i have firebase db follows:

{   "kids" : {     "icon" : "childicon",     "name" : "children's",     "qty" : 2   },   "clothes" : {     "icon" : "mensicon",     "name" : "mens",     "qty" : 12   },   "womans" : {     "icon" : "womansicon",     "name" : "womans",     "qty" : 5   } } 

i want read top level list of names. example, trying retrieve "kids, clothes, womans"

i can use code:

        let query = ref.queryordered(bychild: "name")   //userid)     query.observe(.value, with: { snapshot in         var array = [categories]()         child in snapshot.children {             if let category = mapper<categories>().map(json: (child as! firdatasnapshot).value as! [string : anyobject]) {                 array.append(category)             }         }         success(array)     }) 

to retrieve of items 'name' field, how retrieve string name of above level.

that code return "children's, mens, womans", want "kids, clothes, womans"

any appreciated. doing in swift, accepted!!

thanks