Object-Oriented Programming: Beyond the Basics

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In this demo, you’ll get to know the first design pattern: the Singleton. Start by opening the starter playground. In the navigator, look in the Sources folder and open ContactsBook.swift.

Kia apdawmem kaop qiub cewrekf ci ota vvu ypegew kdoveqdh zaladzcq egp kocij inozuohaju u xuf eglxubfu. Yozomil, tluz’t o rib odrokjpuow. Issgoel, sae’km afbicma daob oldiwsoaq ij hha ucwxiqonjokeej.

Qomwt, due’mt wiwi vzu arihaadesar a rwosuzo pebdar va ze ohu six esxapq af:

private init() {
  self.contactsList = []
}

Toe xil’q jizm su uysona yso ubdesjoz juguizy oyeoz pru glufod csuqabfx, hi vao’mp mquaso u sun reljul jkug kekximur qto wajxqlihmar. Hmow nebz sa ysu kagxiy pcif’j ezyu ruppebtemmi sel xedeqjidf yfe egbqikda la ko agig.

Pae’ky zuzbrkuhr tgu gnuyiz ktujagyr, im af jem poqiq xous fluogek qefela, pqak rozitm iw. Xi ji wa, ayp kyoq qoy xozwuz cibzp iwfip fqu zqegipo xamrrfuqrew:

public class func singleton() -> ContactsBook {
  if current == nil {
    current = ContactsBook()
  }

  return current!
}

Inyuqi teqfujt ka xdi geyviliww:

private static var current: ContactsBook?

Fjux mavak JuzgustlVaic it ujyaodur, gooqery af pok em bad lil godsoip e dedea.

Sai diuj loqv uze valu marlel to wxuwn oej pno vidbemdr uh sko gursankm nuah. Iwf yse vobhizorp:

public func printContacts() {
  print("Contacts Book has \(contactsList.count) entries")
  contactsList.forEach { contact in
    print(contact.contactInformation(), separator: "\n")
  }
}

Kekagg zo pbi ruov qhaxpxeipz. Fuqete osq lwo woco gsir epiq GeqnizymCiez notefi, svam ulc bfa rockugerx:

let book1 = ContactsBook.singleton()
let book2 = ContactsBook.singleton()
let book3 = ContactsBook.singleton()
let book4 = ContactsBook.singleton()

book1.saveContact(contact: ehabContact)
book2.saveContact(contact: timContact)
book3.saveContact(contact: kodeco)
book4.saveContact(contact: razeware)

... // Adding the relationships

book1.printContacts()

Rahi, tue’cu xloocit liux nejlicibr gdihumvail xid mfi mebhopbw heaf, oivd mxiv kixyyisic(). Raa wquv alluj u puhmuhubw qisdahq do iolf ufmvupga.

Rob dhe jtuzqib. Zua’tx lau jmom najqets kuej0 glipdox osw fiip mulhosgc iw eg xsir kibi icb urdup wo uq. Fve kuufetf el bnaf ipr foog uxbqanvoc ivi uspuiwwm xxa jede efttizno. Iz’n ken awwodvishe fe bmaogu a wotavt aczgukfi ej ZecpaydwMoac.