Singleton and Class Properties in Swift - ios

Question

I am trying to create a singleton class. For this I have tried to use two different approaches i.e.
1.First approach - Employee class contains two instance properties, a class property that contains the shared instance of the class and a private initializer, i.e.
class Employee
{
var firstName : String
var lastName : String
static let sharedInstance = Employee(firstName: "Payal", lastName: "Gupta")
private init(firstName : String, lastName : String)
{
self.firstName = firstName
self.lastName = lastName
}
}
2.Second approach - Employee2 class contains two class properties, i.e.
class Employee2
{
static var firstName : String = "SomeFirsrName"
static var lastName : String = "SomeLastName"
}
Are these two approaches of making the singleton equivalent? If yes, which one should I use and what are the differences between each of them in respect of singleton?

Answer 1

To make a simple singletone class in Swift you could write:
class SomeManager {
static let sharedInstance = SomeManager()
}
Usage:
SomeManager.sharedInstance
What does it mean?
Since Swift 1.2 it's possible do declare static class properties. So you can implement the singleton like this. There can only be one instance for the lifetime of the application it exists in. Singletons exist to give us singular global state.
The first approach create a singletone having a class with this initialization: Employee(firstName: "Payal", lastName: "Gupta")
The second approach don't create a singletone, is a simple class with two static declared properties.

Answer 2

These two approaches are not equivalent:
The first approach creates an instance of Employee object
The second approach defines two class fields; it does not create any object instances.
In other words, only the first approach creates a singleton. The second approach makes a collection of related fields at the class level.

Answer 3

Try this...
class Employee : NSObject
{
var firstName : String
var lastName : String
class var sharedInstance: Employee {
struct Static {
static let instance: Employee = Employee(firstName: "Payal", lastName: "Gupta")
}
return Static.instance
}
private init(firstName : String, lastName : String)
{
self.firstName = firstName
self.lastName = lastName
}
}