Singletons
A singleton is a single instance of a class that is present at all times in memory. So why do we care about this? Well, let's say that you are building an app that connects to a database. You need a place to put all of your data service connections. This would be a perfect place to use singletons. Look at the code below; it will show you how to construct a singleton:
// Declaration
class DataService {
static var shared = DataService()
func createUser() {
}
}
// Call-site
DataService.shared.createUser()
If you follow these simple tips, your app will be easier to maintain, and bugs will be more obvious to find before your customers do.