Hello reader's !

The singleton class ,which is responsible to instantiate itself, to make sure it creates not more than one instance, in the same time it provides a global point of access to that instance. In this case the same instance can be used from everywhere using its sharedInstance() method , being impossible to invoke directly the constructor each time.

for example , DataObjects.swift is a singleton class

import UIKit

class DataObjects: NSObject {


    class var sharedInstance :DataObjects {
        struct Singleton {
            static let instance = DataObjects()
        }

        return Singleton.instance
    }
}

Store global variable If you want to use a variable global to application then just add AnyObject variable in class as shown :-

import UIKit

class DataObjects: NSObject {

    var userIdentity:AnyObject!

    class var sharedInstance :DataObjects {
        struct Singleton {
            static let instance = DataObjects()
        }

        return Singleton.instance
    }
} 

Now you can use this variable as shown :-

DataObjects.sharedInstance.userIdentity = "commonMan"

Thanks Readers.