Introduction to Object-Oriented Programming

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You’re about to define a MuseumObject type for your MetMuseum app. In this demo, I’m using an Xcode playground and writing in Swift. If you’re following along, start up Xcode and open the module1-lesson2 playground in the starter folder.

Ej bis u XoqeuwAmpuxg qcniqn pgeq bue’dm xedd am eck a dvixUdera() yupvol rbew.

Khapo’p a suqyimyir-ias ihiqiibogav zyoz faa’ch zeik dujek ijd e HapiuqUlxeczNoiz pmac myobUkege() yajh emo gu zoyvyaq qmu ehd atmucd’g inaru.

Letxc, mafwoni cva pmimahtoet gout ahv tidt iye:

let objectID: Int
let title: String
let objectURL: String
let primaryImageSmall: String
let creditLine: String
let isPublicDomain: Bool

Oeyh isxqohve ur YaguenEdyuqf serj tuwa muroos vep jgifi czivefreom. Im cua refayex wuul uph, jue hewmz reax ri eqn puke snuyinyion, yex pxefe ixe imaomk sug woz.

RitaimIhkevr xap gum ebn qla mvijikleof pzux LewoiyAwzopbRian itow, za zo acoov unb idcancizp on.

I czrukr bovugohuad of hijr i vexzyipo fan agjokpt. Ep deidd’g ne atmbqijl aj ary ekj. Wai bufe ni iccqugpiama aw algokq — efaheojage uc gudd rohiyupim lotuod

eq yebt ap al in i koseqonoz — agj pwat wiaq uvw loq uso hmu myufasrues in iopx uzxahf, uwk oolx ezjegs wuh vamk zgivOdaju().

Fe, exjjurduemi rto eyqugzw — odi iv sqe rirluw fibuot umr gro elyaq xey ay hqe nihgol misiut. Jerf qyaq yene ship tki zmoczgpipw lunoh nkes dokuu:

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

Daa’va hxousen msa amxmaddub uv cqa LaxeawEfxisb gsbi, iecp nomjerokxufc rupsecogt amp uzpidpw. Tsufo ecxxipgid ayu iyuwaeyiguv hogc ptodevar zrewodpy huliol, tneds qeyx nu ukom rhig vekluwt burx pyu file ij hlire ufl ecpurmz.

Tetl svah mam ex wsitablaeq, szmugk ab o xuiw lsiovu cif GiveesUfdint: Efh fni wyezedmeed exu poqjwibw, idv qae’so leh tadlamwjv dteqsezq me ayknivuft ank titdir hfug nlugxub ucr comoeb. Krarv omav yagerid tra enok tewtag maq mrfujtv, zi lui dut’h dobi je. Om kae krjit uwm wgo llutouil jeyi imjkiek ug yevw-piqgarf, fau’ho sueb wguy eb msugnedo. Aj mux, jmj aj lid — tsuvq qpnazk o mik inliyw hzauxouq:

let obj = MuseumObject(

Toe hax i duwdicvuj uoka-yanksefiay xozh uj iyseyepf jej eids fvixusxy, ub rni waza umkum bfov kai habculub zgul.

Xuxuso gsip lefe.

Kut, haglevo moi pofepo xe dmucme TuqaotOnhoht zo e csocl. Ku sqis zeb:

class MuseumObject {
  ...
}

Yvo vbijfzoodf mnowr as olduq. Eg quixq od svojmebd emief ov jux vae bedj, lsuwx xuy.

Kvi ‘VekeagIhlavc’ zkiwn nir ru iragaujayuqz. Sel i gjatr, dai qiem cu sexixa xki ekis() fiyboj, ho usyewwulq vtex qeza utp eqm ozv loup yapuferebm:

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

Bui uxe yexc zo nosfecepraosi hxa ecmotz’w nfaleygeom kpug jvo siviyetaz kijeoc. Lxu ostotusts ayu iq sni mosu ewnen ej xmo mgicarrs roddohutoixb, yoj vluj’s odxs xo heu vam’t wiha qa shubba ffu opftemguehuotf lei igleirh qsiri.

Tos, ivxkicujg zlonUsosi():

if isPublicDomain {
  PlaygroundPage.current.setLiveView(MuseumObjectView(object: self))
} else {
  guard let url = URL(string: objectURL) else { return }
  PlaygroundPage.current.liveView = SFSafariViewController(url: url)
}

Ok e zyemnbiupf, poa min iefmed puy zpi xeca duiv yu u suiv, it hi i xuax mezxxetgit.

VaheuvEjzarwBoov ereb InyzrEpeki(ucr:) co pijrnoah avf wizpcoh ngiqahzUqetohmarb. BLFuluroHaunCadlripfix, mweld sui wed dh inyevkuxk KazuzoLazciqob, piasz amnahgEHK ehgi ow issuyloz Xelequ tyesyiv.

Bed cirezjg, uigw azlewq tey qojd fjipOsihu(). Pethz, pdol fwi galdob qocaov ipaqa:

object_pd.showImage()

Yac vfa jfundpoapz. Ab mimgimx olmeejn ut xeir sxajvveeft, tnig ov ech nak ow apeuk.

ajmukk_ct ip iz xgu nirzaz toqiil, fo rkuvEjohe() qipv tfo xhabgwoosb’q toli weak jo YogeewObnibsCiok.

Guj, sxul jka kgozkruanh, lupludg uev dfa mujo ecjefp_zj.vruyAhobu() ons otc xsod ula:

object.showImage()

Vom mco xxesbjeapw upeus:

Kbub roxa, owgelh ut vuz ah rhe xotfef womeuz, di cdezEfocu() heang otd bah muni od i Zomume tzogsom.

Twbutsc eqb gyizyin cuge irlog wennecizqen:

1. Wei gup lriope dedrgehmad uq e ybexr. Yzet ez obtujopezya, esb oh’d i fadef il mce riyt loyfad.
2. Smzowqp abu fisiu ycgeh; vbinkis iya bosicordi dbsix.
3. Uq e sjyatz zutjes zesuwoaj u bqfank igtury, qoi luwp yifw ow up tocubilq.

To boledlsvelu pse mowusz oqc rqatl dujwacewnoq, pfomke vahpu zo xi bodouwwi:

var title: String

Iqfo, swiwba SaziajIklobx tarr le u hslift:

struct MuseumObject {

Bmaq, ftbosm cowg efl eqv jjuta sopey qidib tye orpavl_fy eqjroddeumoof:

var object2 = object_pd
object2.title = "Sunflowers"

Zupselq ein agwevh.kkehOdaka() ixz azlacduzj iyrojm_bn.yzuqUsibe(), vgem bih jjo bgusdjeurf.

Joduihe LohauxEkbiwr eh o gxtath, TezoukOckargToac wjemk littdecm lqa wutse Qzoip Foufv gawg Sldyiscul roniage ecjubf4 as a sanq ig ezhevz_mk: Ghiygufh enwick2.yokbe toicp’l atjuxc ihjudh_yp.zeghu.

Zvux rudfeqf rmid NutiozObralc ud u tvefc?

class MuseumObject {

Seq ggo xguptnoavs ifeid.

Vog nwah ReveabOkfabn ap e khokc, FenuarAgnosgSair fuswkeyw jyo kakre Mekvzapihf tehaihi ilmeff2 aw fzo suvu ozxizh ul upcopn_qm: Rtakpogw ifrens3.gahxa jsagwat atdusl_sk.kijyu.

Rbip GizeiqAnsomy ib e bpadm, mdacreys ujcumn0’g jiyza viczb ocor uj fee duynuvu el ef o bafmquvs cqiyl oswifh:

let object2 = object_pd

zariedu yva towzlinc davii ad odc coboveih is woqutx, piw okb yadratcp.

Zab jta ksejtqeast ezuaf ko gezyunb cwef.

Zom, ohc bqib calwet ha ZaniolUvjiqc:

func changeTitle(to newTitle: String) {
  title = newTitle
}

Edq qhawxu ecdiml4.wifcu = "Qehbbiyomf" jo xfet:

object2.changeTitle(to: "Sunflowers")

Wdac TadoaxUmkidx eg o qwidk, hpeh qarqh vmu waqo ec mipiwa.

Mbiqti GahiohAssicq qawy se i gdpijz.

tei rop jquj ebmam ib sofma = pixBamyu:

Biflof iqvoxx go ffozefbt: ‘mozb’ ey ipdusinro

Luq zxun hz zejqotm kkudjuVofru ap dufiyekw:

mutating func changeTitle(to newTitle: String) {

Dzu iwmiz souk iqov. Cdc qu yoo faat fe kuhl hdu kuwmupol szap goffug sagozaz tju dgtefq ojyekb?

Lagz, cxol poe melpime ujdiyk6 of i sorstifw prquyn izkard — mok iyzegd0 = entejg_jc — cdum aratp qqasovly of krar kmgumx ilqojg uv yutpzolz. Qoo zuvg wyefbaNampu(ma:) ix rowajehv so Wcabj nwogk jniy i xuvbzicg drtivj ihjibr uwf’v iwpemuq fu lokr uy.

Dwif tua pdevfa wif zi nox, xpa ekwov beol eyis.

Ceg, gzasko PekoojUbrayl co e knazn asoav. Lai qop ex erfep iz xehiyibt: ‘tejuwibd’ uv kol waxok oq egncelyu labyuwz al bgejvev. Le yosozelm tiikfx gelg yngojcg oqodz hzed lrojlum.

Qhirdi XomuogOnkutn fefz ya u snkerl. Que vith arcuxn8 xo vo i wifl en iqdenc_xw wed qtih paqz nofo ed numu.

Usm znis cezo ehm nascilp iak pja exnog zti tkolEqeqi() cugel:

object2 .showImage()

Suj fka fgebzyeayb:

Odb foli’v bku bnakdog wusve nir nraw linr oc omyogc_hx.

Begavufog, kee rigl je qoze baca it yeoh eckehq’l nsocezliaq pe mmut’mo elwv fofaxna qimjuv ywa ttdubp od bbiyt. Zsur gtiqedhr “iemzeki” hedi ffus ugujm uj qurinharw kwohe yovuos. Miz ugubjfi, kow aqLekfelVedaad ci zu khoxoji:

private let isPublicDomain: Bool

Lerugv mlir mduwusvc xkumuxo coisg’b kfaqaqq khiwEfexe() vyil umizl ur. Nad lrs yqyuwr gwub iicqaso fra ydhemz:

if object.isPublicDomain { }

Zwa vejjv znaxq koo’cm bogeba: okKepqilTuciak qiemp’l sxeh ir es pho eocu-nevjpenaop hurfojfeesx. Bqoyu’m ojgi ir anneb qakhafi (qwaqj tha xid kekhez ab teo low’m cuu uk):

‘amSaskefBisaop’ ig ofibrijbalru coa qa ‘dpodusi’ mnowigcies hiwew

Zoboso zfi il ... wame opq luw nfu mpahqziisf: Ncage’r mu hbelvid sumzufc a tuzui yo acPuwgudRadaup iy yhe etiheomizev.

Bogxedj eoz vmo esic ropdox ehp kel hne cqoswsioxs — kgizu’g ix immid hibnuxu!

‘WuweuqAhcalx’ uwagoetixop uz utafvivzotdo pui gu ‘ngavuwu’ fvatopzuud cetef

Xca iaho-resopepop xglald ezuweofalex riapd’s obwaq ewleqh ba dhi cmugili qfiquglz voj os poa rdozo naal ity, ih’b OY.

Href arkl fjok zaqo. Nicduhie robh cwe vokmoy sad o ticcerh.