- (void)savePersonArrayData:(BC_Person *)personObject {
    [mutableDataArray addObject:personObject];

    NSMutableArray *archiveArray = [NSMutableArray arrayWithCapacity:mutableDataArray.count];
    for (BC_Person *personObject in mutableDataArray) { 
        NSData *personEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:personObject];
        [archiveArray addObject:personEncodedObject];
    }

    NSUserDefaults *userData = [NSUserDefaults standardUserDefaults];
    [userData setObject:archiveArray forKey:@"personDataArray"];
}

//: Playground - noun: a place where people can play

import Foundation

class Person: NSObject, NSCoding {
    let surname: String
    let firstname: String

    required init(firstname:String, surname:String) {
        self.firstname = firstname
        self.surname = surname
        super.init()
    }

    //MARK: - NSCoding -
    required init(coder aDecoder: NSCoder) {
        surname = aDecoder.decodeObjectForKey("surname") as! String
        firstname = aDecoder.decodeObjectForKey("firstname") as! String
    }

    func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeObject(firstname, forKey: "firstname")
        aCoder.encodeObject(surname, forKey: "surname")
    }
}

//: ### Now lets define a function to convert our array to NSData

func archivePeople(people:[Person]) -> NSData {
    let archivedObject = NSKeyedArchiver.archivedDataWithRootObject(people as NSArray)
    return archivedObject
}

//: ### Create some people

let people = [Person(firstname: "johnny", surname:"appleseed"),Person(firstname: "peter", surname: "mill")]

//: ### Archive our people to NSData

let peopleData = archivePeople(people)

if let unarchivedPeople = NSKeyedUnarchiver.unarchiveObjectWithData(peopleData) as? [Person] {
    for person in unarchivedPeople {
        print("\(person.firstname), you have been unarchived")
    }
} else {
    print("Failed to unarchive people")
}

//: ### Lets try use NSUserDefaults
let UserDefaultsPeopleKey = "peoplekey"
func savePeople(people:[Person]) {
    let archivedObject = archivePeople(people)
    let defaults = NSUserDefaults.standardUserDefaults()
    defaults.setObject(archivedObject, forKey: UserDefaultsPeopleKey)
    defaults.synchronize()
}

func retrievePeople() -> [Person]? {
    if let unarchivedObject = NSUserDefaults.standardUserDefaults().objectForKey(UserDefaultsPeopleKey) as? NSData {
        return NSKeyedUnarchiver.unarchiveObjectWithData(unarchivedObject) as? [Person]
    }
    return nil
}

if let retrievedPeople = retrievePeople() {
    for person in retrievedPeople {
        print("\(person.firstname), you have been unarchived")
    }
} else {
    print("Writing to UserDefaults is still broken in playgrounds")
}

NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:yourObject];
[currentDefaults setObject:data forKey:@"yourKeyName"];

NSData *data = [currentDefaults objectForKey:@"yourKeyName"];
yourObjectType * token = [NSKeyedUnarchiver unarchiveObjectWithData:data];

[currentDefaults removeObjectForKey:@"yourKeyName"];

class ArchiveUtil {

    private static let PeopleKey = "PeopleKey"

    private static func archivePeople(people : [Human]) -> NSData {

        return NSKeyedArchiver.archivedData(withRootObject: people as NSArray) as NSData
    }

    static func loadPeople() -> [Human]? {

        if let unarchivedObject = UserDefaults.standard.object(forKey: PeopleKey) as? Data {

            return NSKeyedUnarchiver.unarchiveObject(with: unarchivedObject as Data) as? [Human]
        }

        return nil
    }

    static func savePeople(people : [Human]?) {

        let archivedObject = archivePeople(people: people!)
        UserDefaults.standard.set(archivedObject, forKey: PeopleKey)
        UserDefaults.standard.synchronize()
    }

}

class Human: NSObject, NSCoding {

    var name:String?
    var age:Int?

    required init(n:String, a:Int) {

        name = n
        age = a
    }

    required init(coder aDecoder: NSCoder) {

        name = aDecoder.decodeObject(forKey: "name") as? String
        age = aDecoder.decodeInteger(forKey: "age")
    }

    public func encode(with aCoder: NSCoder) {

        aCoder.encode(name, forKey: "name")
        aCoder.encode(age, forKey: "age")

    }
}

var people = [Human]()

people.append(Human(n: "Sazzad", a: 21))
people.append(Human(n: "Hissain", a: 22))
people.append(Human(n: "Khan", a: 23))

ArchiveUtil.savePeople(people: people)

let others = ArchiveUtil.loadPeople()

for human in others! {

    print("name = \(human.name!), age = \(human.age!)")
}

let myData = NSKeyedArchiver.archivedData(withRootObject: myJson)
UserDefaults.standard.set(myData, forKey: "userJson")

let recovedUserJsonData = UserDefaults.standard.object(forKey: "userJson")
let recovedUserJson = NSKeyedUnarchiver.unarchiveObject(with: recovedUserJsonData)

- (NSUserDefaults *) defaults {
    return [NSUserDefaults standardUserDefaults];
}

- (void) persistObj:(id)value forKey:(NSString *)key {
    [self.defaults setObject:value  forKey:key];
    [self.defaults synchronize];
}

- (void) persistObjAsData:(id)encodableObject forKey:(NSString *)key {
    NSData *data = [NSKeyedArchiver archivedDataWithRootObject:encodableObject];
    [self persistObj:data forKey:key];
}    

- (id) objectFromDataWithKey:(NSString*)key {
    NSData *data = [self.defaults objectForKey:key];
    return [NSKeyedUnarchiver unarchiveObjectWithData:data];
}

NSMutableDictionary* dictionary = [NSMutableDictionary dictionaryWithDictionary:dictionary_trying_to_save];
[dictionary removeObjectForKey:@"NullKey"];
[[NSUserDefaults standardUserDefaults] setObject:dictionary forKey:@"key"];

struct User: Codable {
    let id: String
    let mail: String
    let fullName: String
}

struct Pref {
    static let keyUser = "Pref.User"
    static var user: User? {
        get {
            if let data = UserDefaults.standard.object(forKey: keyUser) as? Data {
                do {
                    return try JSONDecoder().decode(User.self, from: data)
                } catch {
                    print("Error while decoding user data")
                }
            }
            return nil
        }
        set {
            if let newValue = newValue {
                do {
                    let data = try JSONEncoder().encode(newValue)
                    UserDefaults.standard.set(data, forKey: keyUser)
                } catch {
                    print("Error while encoding user data")
                }
            } else {
                UserDefaults.standard.removeObject(forKey: keyUser)
            }
        }
    }
}

Pref.user?.name = "John"

if let user = Pref.user {...

//MARK:- First you need to encoded your arr or what ever object you want to save in UserDefaults
//in my case i want to save Picture (NMutableArray) in the User Defaults in
//in this array some objects are UIImage & Strings

//first i have to encoded the NMutableArray 
let encodedData = NSKeyedArchiver.archivedData(withRootObject: yourArrayName)
//MARK:- Array save in UserDefaults
defaults.set(encodedData, forKey: "YourKeyName")

//MARK:- When you want to retreive data from UserDefaults
let decoded  = defaults.object(forKey: "YourKeyName") as! Data
yourArrayName = NSKeyedUnarchiver.unarchiveObject(with: decoded) as! NSMutableArray

//MARK: Enjoy this arrry "yourArrayName"