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Question

I try to make an app that shows the proximity of beacons. I made a label to receive this data, but I can't, and i want to just show "proximity" not all this data that shows in console. I try with beacons[3] but the program gives me a error.

import UIKit
import CoreLocation

class ViewController: UIViewController, CLLocationManagerDelegate {

    @IBOutlet var metrosBeacon: UILabel!
    let locationManager = CLLocationManager()
    let region = CLBeaconRegion(proximityUUID: NSUUID(UUIDString: "FDA50693-A4E2-4FB1-AFCF-C6EB07647828")!, identifier: "MKT BEACONS")
    // Note: make sure you replace the keys here with your own beacons' Minor Values


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        locationManager.delegate = self
        if (CLLocationManager.authorizationStatus() != CLAuthorizationStatus.AuthorizedWhenInUse) {
            locationManager.requestWhenInUseAuthorization()
        }
        locationManager.startRangingBeaconsInRegion(region)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func locationManager(manager: CLLocationManager, didRangeBeacons beacons: [CLBeacon], inRegion region: CLBeaconRegion){
        print (beacons)
        metrosBeacon.text = "/(beacons)"

    }}

Console data :

[CLBeacon (uuid:<__NSConcreteUUID 0x12ee586c0> FDA50693-A4E2-4FB1-AFCF-C6EB07647828, major:10004, minor:54480, proximity:1 +/- 0.05m, rssi:-32)]

Thanks Guys!!

Answer 1

We see in locationManager 's signature that beacons is an array of CLBeacon objects:

func locationManager(manager: CLLocationManager, didRangeBeacons beacons: [CLBeacon], inRegion region: CLBeaconRegion)

And we see that you get one object in the array:

[CLBeacon (uuid:<__NSConcreteUUID 0x12ee586c0> FDA50693-A4E2-4FB1-AFCF-C6EB07647828, major:10004, minor:54480, proximity:1 +/- 0.05m, rssi:-32)]

So, get this first object from the array, then get the value from the property:

if let beacon = beacons.first {
    print(beacon.proximity)
}

Of course, if you have several beacons in the array, you may use a loop:

for beacon in beacons {
    print(beacon.proximity)
}

Answer 2

CLBeacon is a subclass of NSObject , thus is has a method called description() , which returns an NSString containining the description of the object.

When you call print(beacons) , you're calling print on an argument of type [CLBeacon] (aka Array<CLBeacon > , or an Array of CLBeacon objects.). print doesn't itself know how to print CLBeacon objects, so it asks the CLBeacon for its description() , and prints that.

The output:

[CLBeacon (uuid:<__NSConcreteUUID 0x12ee586c0> FDA50693-A4E2-4FB1-AFCF-C6EB07647828, major:10004, minor:54480, proximity:1 +/- 0.05m, rssi:-32)]

represents an array of a single CLBeacon object, whose description` is:

CLBeacon (uuid:<__NSConcreteUUID 0x12ee586c0> FDA50693-A4E2-4FB1-AFCF-C6EB07647828, major:10004, minor:54480, proximity:1 +/- 0.05m, rssi:-32)

To get just the proximity, we can look into the class documentation for CLBeacon , and see that it has a proximity variable we can get.

We can print all proximity with something like:

for beacon in beacons { print(beacon.proximity) }