cannot use instance member 'ref' with the initializer error - swift

Question

I am facing this error all is well, I want to print the children of "12356" in console but i am getting this error i dont know why this is happening and here is the Firebase structure
and this is the xcode error
and here is the code
import UIKit
import Firebase
import FirebaseDatabase
class TestViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
var ref = FIRDatabase.database().reference()
let root = ref.child("Items").child("Flate").child("12356")
root.observeSingleEvent(of: .value, with: { snapshot in
if !snapshot.exists() { return }
//print(snapshot)
if let myfRateA = snapshot.value["fRateA"] as? String {
print(myfRateA)
}
if let myfRateB = snapshot.value["fRateB"] as? String {
print(myfRateB)
}
})
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

Answer 1

You did not put your code into the right place, because it is outside any method or function. Put it inside a function's body like so:
func printChildren(){
let ref = FIRDatabase.database().reference()
let root = ref.child("Items").child("Flate").child("12356")
root.observeSingleEvent(of: .value, with: { snapshot in
if !snapshot.exists() { return }
//print(snapshot)
let myfRateA = (snapshot.value as? NSDictionary)?["fRateA"] as? String ?? ""
print(myfRateA)
let myfRateB = (snapshot.value as? NSDictionary)?["fRateB"] as? String ?? ""
print(myfRateB)
})
}
And call it in viewDidLoad() like so:
override func viewDidLoad() {
super.viewDidLoad()
self.printChildren()
}