Storing Coordinates in User Defaults Swift

User Defaults is a built-in feature in iOS that allows you to store small amounts of data as long as the app is installed. In this article, we will explore how to store an array of coordinates using Core Location in User Defaults.

Firstly, please note that User Defaults are only available in sandboxed environments and not in Playgrounds. To use User Defaults, import the `CoreLocation` framework and create a function to store the array of coordinates.

Here is an example of how you can do this:

```swift

import CoreLocation

func storeCoordinates(_ coordinates: 'CLLocationCoordinate2D') {

// Convert the array of coordinates to data

let data = NSKeyedArchiver.archivedData(withRootObject: coordinates)

// Store the data in User Defaults

UserDefaults.standard.set(data, for

}

```

To retrieve the stored coordinates, you can use the following function:

```swift

func retrieveCoordinates() -> 'CLLocationCoordinate2D'? {

// Retrieve the stored data

let data = UserDefaults.standard.object(for

// Unarchive the data to get the array of coordinates

guard let unarchivedData = try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data!) else { return nil }

// Return the array of coordinates

return unarchivedData as? 'CLLocationCoordinate2D'

}

```

In this example, we use `NSKeyedArchiver` to convert the array of coordinates to data and store it in User Defaults using the `set` method. To retrieve the stored coordinates, we use `NSKeyedUnarchiver` to unarchive the data and return the resulting array.

Note that `CLLocationCoordinate2D` conforms to `NSSecureCoding`, which allows us to archive and unarchive instances of this class. However, if you have a custom object that does not conform to `NSSecureCoding`, you will need to implement your own archiving and unarchiving logic.

In conclusion, storing an array of coordinates using Core Location in User Defaults is a simple process that involves converting the array to data and storing it in User Defaults. By using `NSKeyedArchiver` and `NSKeyedUnarchiver`, you can easily store and retrieve custom objects from User Defaults.

Store in user defaults swift