How do I check if a firebase database value exists?

Question

I'm using the Realtime Database with Google's Firebase, and I'm trying to check if a child exists.

My database is structured as the following

- / (root) -   /users/ –-    /james/ --    /jake/ -   /rooms/ --    /room1/ ---      (room 1 properties) --    /room2/ ---      (room 2 properties) 

I would like to check if room1 exists. I have tried the following:

let roomName:String = "room1" roomsDB.child(roomName).observeSingleEventOfType(.Value) {  (snap:FIRDataSnapshot) in     let roomExists:Bool = snap.value != nil ? "TAKEN" : "NOT TAKEN"  } 

In accessing snap.value it returns a JSON of the properties of that room, but how would I check if the room (/rooms/room1/) is there to begin with?

Comment if any clarification is needed

Answer 1

self.ref = FIRDatabase.database().reference()     ref.child("rooms").observeSingleEvent(of: .value, with: { (snapshot) in          if snapshot.hasChild("room1"){              print("true rooms exist")          }else{              print("false room doesn't exist")         }       }) 

Answer 2

While the answer of @ismael33 works, it downloads all the rooms to check if room1 exists.

The following code accomplishes the same, but then only downloads rooms/room1 to do so:

ref = FIRDatabase.database().reference()  ref.child("rooms/room1").observeSingleEvent(of: .value, with: { (snapshot) in     if snapshot.exists(){         print("true rooms exist")     }else{         print("false room doesn't exist")     } })