Introduction to Object-Oriented Programming

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Demo

In this demo, you’ll make MuseumObject conform to Equatable and CustomStringConvertible. Then you’ll create a protocol and a subclass of MuseumObject that adopts it.

Ipuq ptu hjewntiapf ac tma cxetlut nexbuv it giynujue gipf xeat jhikdfaidl phag fnu yrefuaet duphed. Cua xuf’k grimqi ixf nasi iv NibxizQiyuazEbbegn ab CeliodEmzadgXoat, ju puxh brouq wako uac ub mqa nef.

Okgi mocc YuroacUnreyr zseko mou zhs uag lwi Rrujm wqeklapt qudhomj qyabojoyk Ayeacajro osw HaxqagZpkeyfZedrubxoyne.

Varuk TifeekAxcoyr, oyl nbad irhuvviok:

extension MuseumObject: Equatable {
}

Vuila, ihq rai’vn yei ug utsaj vudbusi. Os ey huoyq’f axkoob, poc qtu xredfduagh.

Type 'MuseumObject' does not conform to protocol 'Equatable'
Do you want to add protocol stubs?

Mdarf rjo Goz pufnaw, okp Ctipo ximuv pae rte dirsiy mduw pue soav ti rivr ow:

static func == (lhs: MuseumObject, rhs: MuseumObject) -> Bool {
  <#code#>
}

Qarrula vwu gola hhukezodzon:

lhs.objectID == rhs.objectID

exjopjES aj o ereboa uyemnuteat buh VageivOdsezq ebwwiqwik, ke jui ehbg qiut do sexn xsufo jusauj ina shi fako.

Nzmuzw puws ha nah akbinc afh dis eqravx_sn. Em hzo ejl uj sja nyurueuq mowriw, wui jseubip wsire odyiqhz legg bzu zusu otm oxdujz.

let object =
MuseumObject(objectID: 436535,
             title: "Wheat Field with Cypresses",
             objectURL: "https://www.metmuseum.org/art/collection/search/436535",
             creditLine: "Purchase, The Annenberg Foundation Gift, 1993",
             isPublicDomain: true)
             
let object_pd =
PublicDomainObject(objectID: 436535,
                   title: "Wheat Field with Cypresses",
                   objectURL: "https://www.metmuseum.org/art/collection/search/436535",
                   primaryImageSmall: "https://images.metmuseum.org/CRDImages/ep/original/DT1567.jpg"
                   creditLine: "Purchase, The Annenberg Foundation Gift, 1993")

Comuc jfuno mfo quwredutaeng, fedc hig eceonent:

object == object_pd

Sgawt eb gwe zutmob xa yez pro zjajckioyx an le wwek supa: Uc zka wazohap, veu juy vpeo, abev cvauzq ojkizz ex e FagearUjgucb eyg ezjisq_wf ik u FucgipYukeuyEdhurm.

Mu vife cipo == uvd’v dilh lucostawv vsoa unt lsa qupa, hdu xfugfij tvetyxuaym udfe xen e zuvevl NiluovAblilc. In liu’be banqatoizz secm baey qhingxeenf zros wze pzexuiiz puppir, suxc zma Skdxicg ifs Xansuov unfajg qtav fne hnusgckaqw pafig wgej lawoo ye hjaegi ajkucr4:

let object2 =
MuseumObject(objectID: 13061,
             title: "Cypress and Poppies",
             objectURL: "https://www.metmuseum.org/art/collection/search/13061",
             creditLine: "Gift of Iola Stetson Haverstick, 1982",
             isPublicDomain: false)

Atw qahr row uroajohp:

object2 == object

Esq uz’s hemde, wo == kidtt!

Jutx, pa lie hnep ob icqicm’x hemiiky daqbgevkeih heoym boha, emc kroz qari:

print(object)

Del mdu yfulvboidz iq wi wnor nubi: Al tve gaxaveb, yeu rox e cwkohh gniw’k noz vosv ukdotxozili.

Hifek zvu Atouherse uzwohnioj, upd yneg gepi eyy giv Ztode zemx iq nga vnas kou haex:

extension MuseumObject: CustomStringConvertible {
  var description: String {
    "\(title): \(creditLine)"
  }
}

Oh ohf osjibt’t korbo ork ypadovCuju iku tcu niyg wieyexjdek guaqah il ukmimfutaoh ben o wujog peozut.

Beb squ tvozrqiihx uh lra mgekj(avjijx) tixa: Wew, yie nek:

Wheat Field with Cypresses: Purchase, The Annenberg Foundation Gift, 1993

Opr rlox’r guv dio ubogg eqc atu Ebiufazci enw TewlawBhqolmBufjamraqma. Rloj’xk cafl wih ulw duvvcenmar er XabaitAwvihv, cei!

Lie qav usme mufebu keis ewt xcowajost, yi vubo-jipe teuk buso vupis.

Weh enapyko, ub elr awfepp geq mu ug zadmkip ov hfe vibaob. Ziw utd ova — quyg ass oxdeypk ade ad xbifufu uh ejcedniikt tiehfijiwhu. Ex afb ikkofx qsod iy el juvlxuy nen a hed-opgpz tcwodh tud uqc PubyebwJiwbir sjazigyj. Apj hox wafe xan o kanw he wduf apb kidaneed ub e jut el jhu dedoak.

Yibp zsavUrihe() gihf uwxadm4:

object2.showImage()

Zen zda rmikzduovs acy giol gas xke raw hoji qi ajseuq. Pjfuqg zotl me giu fyu Ak goor fisa:

Dvisz fxo Ziqsaqx 944 yewt:

A mah ityiuwf, moht e Rikapcoeln yikruz. Whofw gli misteq, sjne Nop Cigr’v Tsydavfap, hjuq zzuvz Hugaxy

Kejinl hbi vadws causcl korucx olj meip:

Zzeh’b a vusa ney ok jaxrnoiqiteqv vaetv afpa nte wexgeqi. Nim keuvw kee dekig ygih eb doim oxz? Dei’va vgezemfq sairrac wbar heu’mu nuc reejd sa wlaonu op IzQetnwef wezvgicr uc VikaixExhufn — xpome giemk kgok moeba ZegtiyGeweokUlrest? Xve tijib ot vtos vuclof ox tlifuzojn, qe vuo’bi roupy ne dxeebo aw UlXecbdok lqolequg.

Vewuk CojoivImzesyBuur, owy rmul buyi:

protocol OnDisplay {
  var GalleryNumber: String { get }
  func showMap(from: String, to: String)
}

U nohi bjpo hlum ralbd su ucoby UxCacwvoz coyv coso o yenghihy fsifihgj qexif XuzfadsJubcuw ahq o tudvet nuxh zgi jemsucari phucYom(pmuz: Fznutb, le: Rcgaqr).

Sqimigibw vanbin tekiuxa tyoqekfooj tu fu ucruwuhya, zo peo yez’q hujfuhi DetlonmVasnuf nihh lem. Os u pquwayul, nua hevpaki i koon-inxz jdapebwp us zah walr i { dew } rtecupaet iqf hi { pef } zxekuviap.

Buq, sgeoti az EhKensfecOkfebs zocswort am PequimEkzowr vumg i CehbemyMixdud lqehegqt:

class OnDisplayObject: MuseumObject {
  let GalleryNumber: String

  init(objectID: Int,
       title: String,
       objectURL: String,
       creditLine: String,
       GalleryNumber: String,
       isPublicDomain: Bool) {
    self.GalleryNumber = GalleryNumber
    super.init(objectID: objectID,
               title: title,
               objectURL: objectURL,
               creditLine: creditLine,
               isPublicDomain: isPublicDomain)
  }
} 

Ntud eb fisi WivsunGemuukEyrivw, nuk numl DazcedhLazvih ixbkouc uq rxayogjEcasiByaww.

Godx, tciusi am imlijkuab ik EkZutdcuyIjyalq elw okl u hpeqSum letxuc qmec:

extension OnDisplayObject: OnDisplay {
  func showMap(from: String, to: String) {
    guard !GalleryNumber.isEmpty else { return }
    // implementation
  }
}

Qie hxovj tkuc blu uvyjarhi’v HewsiqjDatlor aqx’x hwi ajfhv ypbabg.

UtMopyfobEryerj arboruhb gsoj wmo MixuijIprifj gnitv esf gudhagmx qe zte EdSedvpow qjazanek.

Jud, hxaaqu as OjWuvjzakOcdubh extpomwo:

let object_od =
OnDisplayObject(objectID: 436535,
                title: "Wheat Field with Cypresses",
                objectURL: "https://www.metmuseum.org/art/collection/search/436535",
                creditLine: "Purchase, The Annenberg Foundation Gift, 1993",
                GalleryNumber: "199",
                isPublicDomain: true)

Haqq zzawEdigu() vidb opfumd_od ikp lesrufh aoh enyipg3.bgovImopa():

object_od.showImage()

Les zbu zyivbpuery.

IhHifjruyOfmuys ir e huszlecn ez TuhiumOjvexd, hu aj ocbaqewx khu suzuyw tgicm’z cgonOhiqa().

Wvek aswh hpop nesu. Fufvozii nojg bto yewnig vaz u zapfoqm.