Access a let/var in another method Swift - ios

Question

I'm currently developing with CoreBluetooth and I've managed to get the RSSI-strength. I can print it in the console, but when I want to use it in an IBAction, it wont work. I guess it's because the RSSI var isn't a local variable.
Here is the method where I get the RSSI-strength from:
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
let device = (advertisementData as NSDictionary).object(forKey: CBAdvertisementDataLocalNameKey) as? String
let rssi = RSSI // The const that stores the RSSI-data
print(rssi)
if device?.contains(BLE_NAME) == true {
self.manager.stopScan()
self.peripheral = peripheral
self.peripheral.delegate = self
manager.connect(peripheral, options: nil)
}
}
And here is the IBAction that I want the rssi const to be in:
#IBAction func btnPressed(_ sender: Any) {
rssiLbl.text = "\(rssi)"
}
However, I don't know how to make this work. I bet that this is a really basic question for the most of you, but I just can't make it work.

Answer 1

As others have said. Declare rssi as a class-level variable:
private var rssi: NSNumber?
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
let device = (advertisementData as NSDictionary).object(forKey: CBAdvertisementDataLocalNameKey) as? String
self.rssi = RSSI
print(self.rssi)
if device?.contains(BLE_NAME) == true {
self.manager.stopScan()
self.peripheral = peripheral
self.peripheral.delegate = self
manager.connect(peripheral, options: nil)
}
}
#IBAction func btnPressed(_ sender: Any) {
if let rssi = self.rssi {
rssiLbl.text = "\(rssi)"
} else {
rssiLbl.text = "Undetermined"
}