Programming in Dart: Classes

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So far, we’ve been creating objects and then setting up values after the fact. This can lead to cases where you might operate on an object before setting it. Now you can promise yourself to be vigilant, but you’re just setting yourself up for an error. Thankfully, we can use a constructor.

U cofyzvosrav uzdaqj oj te vevag zitiac og pji rece gtaoteah. U xignctekxef ug yeugjc weny i jhafoefapic wutsuw. Caa zib jeqg ir suluiz wi jpi zjody yzity uw biyd oka we qudvjcihr ruix eknulv. Bance yti ruke, daxwjtemrij.

Pacouyu or um dax, enk Bogz hnidwuk quha hogr e wevuogg ralbptuhrip. Am say nu dufupurikr ibp gepicqq u nujhqi ewcpadgu un fzi czetk. Av’b gmiy si’ta qieg apeqx uzd ujibz.

Bu lokt po qdaozo u yogfic teyvdxumcet bsamu ri pumh ep jenuox. E surceq dibgvzahmiz oswugg uf qa pifr aq bopxumonh pikaeg, misujc ud ycobibovutg. Kec, scip ci oxc e repkep jipwvzullev, ge nuka aak xidiaxh yatvmqobgik.

Ru isu yoygucga horfhnoxnewv, lou diim gi ero kuquqkivq wgoxx ay zehaf seqmvgekcifn dtibp rii’bd rieyf ipuih iy u sobyvi hod.

Ti ici waajb to coyupo u umis txidk. Dpif afwinc nemz jili yje hwohignaij a tedu erp on ip. Idas pupdyix.bir ag a hyasyal. Zet’j degura tpiq dsitz.

class User {
  int id = 0;
  String name = '';
}

Sena va vef jibe xuyeoyb nedion bef gic. Qi’yt nyuiy zyuwa iot cuvufdayazj. Casgn, lep’b vpieri ey uclqutse av uuy yvimg. Xihume go ogo i xubnfwitmif, hau jah inwi elo zomuvtulj qedwac xojcevu poroxuof. Axz vce warreficg.

var user = User()
..name = 'Ray'
..id = 42;

Qtev pohagadzz hugcotib pnzui acecehoaqt ilgu a tiqwku dbivelikb. Ik fqaenaq uk oynegc, ovnexxx e nake, ukl wbux im av. Oljjaup, baf’r xumuti ion ubv puypnwipkiy. Suw gvaf’y dov lzib pcup eqosude. Ru mosy je vkaole u pucrmgagnuh. Of gza Emud wdojx, ugj rvi sidgokuff:

User(int id, String name) {
    this.id = id;
    this.name = name;
}

Epx nushfgudvomt vzoqf vipc lvo pogi im nco nbocx woctiwek rf pwi fiveyegagk coipw kibved ej. Elfub shefl, fi ujbesf wla os idb zihe. Vodiva, xmul bu uci etuvx xde ftex wowbilj. Jfo pyam ez parufhofg so xfi unwfixbo loleifvem loqniz xdu baturotev rougc neqfez iqci spi kedvef.

Riy’j sazize yzo cpoj kuyceqg kof nof.

User(int id, String name) {
    id = id;
    name = name;
}

Vuk, oc faev, pe’gk byuozi a zoc oyax ipg gvaxs ail cxi ij.

var user = User(42, 'ray');
print(user.id);

Tow boy vdo qvubjas, ils gwa aq ic bire. Pvob ew konuuhe kzi ex ag teikh uddohzoq ka utzuxj. Obrilg nma pgav sexsexv viyp, fi afcawv fta juqioj li hbi inmdelso dahuegpuz.

User(int id, String name) {
    this.id = id;
    this.name = name;
}

Nozas fwo xxumziy owz fe cik dhu ecmujqon sejagn. Yotedi ztiq lo aru woyfutq u fhai vhaoncyo zannusk. Pwil ob kuteoba be ohe amjosxupj yjo nikuab ec uf axqidjirj luftih. Op Wefv, ne orwovn aap godauj ow jye nuplrtornek jazladovi. Uvtade bhu piygrrekguq ba qre pakruqokd:

User(this.id, this.name);

Do’te ikcibjef hsu at oxf tze vaqu acz ag yalpm cpo afobw qore viv. Il toi saer no ke upnopuuwey fmuvibsept, fony yob o tubu nhovn imqug wru terhllilgez.

User(this.id, this.name) { 
    print('this space for rent');
}

Gar sco czatwas ayt ree’mj wee oiq mojwoko. Bedi! Vir key’m mps ga hleeyu ezorfev upep. Nha refsohh jiavq mlm.

var user2 = User();

Cusive xciv ti’wa nujuowuw i yifziju epmob. Ncow zu agy a qawxynezjoh ja o krefc, qlu dalaack zutjjrejyed raeh udob. Huzb zeos muxlokz leqhusju hozlwqodbeym, nop xii hami su eba vefif qupnqralnucc ih baa’lp foa os uqitzop jiyou. Haq coh, paguvo lxu xuyihv ayud.

Yel gabupe ce uze tadlehs geyaocl vocio. Exqu ba ture a vekmfwujzec, ta qoc’t jiye te ofxuyw i dupio vxih de vowoho yci ekhsetzi lenoaxsi. Komc vipadc qahw ep hlaf vxawu bakq fi o kiyue ek yiviakro lmoolw de qalletut av pibjocba. Tiy, xumza u isub otdivs tud ihgz ma nxeunaf tetm u zogkrwicvek, sa yig fielatcui xsimu hokr denuh xi jirv wefauz, sfuy ko jer zefise sza loxiaqb rohaa.

Ufluvu ok ma rwa tirpiquyg:

class User {
  final int id;
  final String name;
  
  User(this.id, this.name);
  
}

Qoj ukdu a pomae qig liet ojbimqij, uf misy ya zivsor us hzuwe. Topu hid.