快速访问嵌套键/值对

Question

I am trying to access the value of the key 1. Here is my Firebase diagram:

And here is my code:

@IBAction func ridefinder(_ sender: Any) {

    let ref = Database.database().reference()
    ref.child("name/hi").observeSingleEvent(of: .value) { (snapshot) in
         print(snapshot.value as? [String:Any])
    }

When I run this it prints nil , however when I change it slightly to this:

@IBAction func ridefinder(_ sender: Any) {

    let ref = Database.database().reference()
    ref.child("name").observeSingleEvent(of: .value) { (snapshot) in
         print(snapshot.value as? [String:Any])
    }

it prints both sets of key-value pairs inside.

How do I just access the value of the key hi inside name?

Answer 1

Try:

let ref = Database.database().reference()
ref.child("name").observeSingleEvent(of: .value) { (snapshot) in
     if let value = snapshot.value as? [String:Any], let hi = value["hi"] as? String { 
         print(hi)
     }
}

Values inside database references are accessed by using snapshot.value and being casted as [String: Any]. And then you find your desired values inside dictionary like always accessing them as dictionary["key"].