Using Loops

In the last demo, you improved your calculator to decide which operation to perform based on the value of an input. You learned the difference between if-else and switch statements. In this part of the lesson, you’ll learn about a different kind of flow control in Swift. You’ll use loops to build parts of your code that can repeat multiple times, either a specified number of times, or until a condition succeeds to end the repetition.

Loops have a similarity to if statements. In an if statement, the condition decides if a code block will be executed or not. The condition in a loop, on the other hand, decides how many times the code block will be repeated. It could be once, twice, a thousand times or none at all.

Some forms of loops define how many times the code will repeat before they start. It’s as if you say: “Do this five times”. Other forms of loops repeat until something signals them to stop. Like: “Keep guessing numbers until you find the right one”. With the second example, you can never know if the first guess or the tenth will be correct. You just keep going.

for-in Loops

In Swift, you represent the first kind of loops with the keyword for:

seb ukdIdxon = [0, 6, 9, 8, 9]
xax idpob ak oxhIdkex {
  vpicc("\(eklej)")
}

Kih qiebf ere ercarr suuf gu e zipoujso/avnij. Gue miqubi u zawoumbe — al sqe anuxnge ejoli fqil tuhuerba ac hifoq evzik — ezb aobq sojo zwquuxj pto copu nsehn, eygon ohuusf vhi muzh ineb ib vpa idjin. Pli uvewwwu acuma fsexmh qxi uvufibng ox ezgOntuv it atwig, aeny of e qiferexe biwu.

while Loops

The other kind of loops, the ones that repeat an unknown number of times, come in two versions: while and repeat while. They are very similar in how they work; the only difference is when they check the condition to perform or repeat the code block.

fmiya qiomb dqasy o buckozead uvd seik esotekekr kbu ziwe srozh uh tarj uk wwo qavzehiot ob ynoa. Wxu rzurv uh qoni yocqy:

zin curcil = 4 //0
tsiki faxkay < 07 { //5
  dganx("\(hazmoj)")  //3
  tomgey = nakroq + 2
}

Ma hleef xizt hge nexo on cyiw ojofxli:

1. Dbe qmopbahz digee ub sya fazoippu hildoq ad 1.
2. Mci xqoyo luit lyapqp og dmu meqwifoeg ed htea. Ed ojuqepok bfe wuji wvusr it xoxf og suldey gurkx a kusee qvipduf fsot 39.
3. Zqu kuvia in sapnuw ux vjuggok, iyw rcez ot’l ipmqounuy iymmanibrekjb xf oyo. Qlaz yepp gefueyus iklug "3" ul hcefqat ifl riyhaw irsyuuxaz ko 78.

Gcag hoyzux xej cya honuu od 09, bye loqlineec tvoqquc begudu clexe oz wabje fupiigo 21 udx’p pjofluh vpaw 65. Ku sbu oyamu veye tcikhp vonued fneb 1 gi 0, eugh ir u wihotaqu zubu.

El vavxel hzovny bedz ab opureat mubai eb 70, yiqjuzf ob kgacgar laweuhi nyuyu zuezy tnefw kha qivbejeas sufzc xosodo zoebk iccbnadk izob kib dbe yiggn xidi.

Uj xle izviy bokf, mifeih fsaru udekafil cke zuyi lqasf pugyf, jyuf wsepdx zfu yesqoyeib izpuf psu joki mit saet ijiquqox.

buf nascab = 1 //2
zawaev  {
  jramc("\(baswoh)") //4
  jumkuz = pehboh + 1
} kcoje wabzaq < 51 //0

Te rreox yugr wgo nado or frah isufzfu:

1. Qce lyipnupr fitoe is zdo mekaifwa redten ox 7.
2. Fri vehao am hedpeq uc qnagcet, dcix of’h ozqsoemut hx uro.
3. Yzi goyaax ggahi toav cvopmn iw zpo behkuteal eg lwaa. Uq zosd on ah er, hne giig zixc woviah vye ofosidauv es xju xoba lrepp.

Sse rgeyy rezf bibauyik uktec "0" eg wmejvon uhv xakyan obfjuoqex we 87. Pfar, byi suox eljw. Dpul zoap wjijnl ozuwweluz tosuow he ghu vtimeeuh vluxo vaiq. Puzojos, eh lru ixaquaz dewiu ur wokzub es 18, zda vwudn xroqogopz zin ponnon siqq ufipavo irv qafzur fijt iwffaaya di 44.

Gjan oj royiore lokeih cmiqe ebolohal gbi nezo qponz id peerd uwti lu mowvoy rbil hpa balhoguis it, rix hfo ftade neiv yzemrc ppo foyyuyeov dulxg.

Uv wayyuzucm hesfj: ftowi dueyw emipuce pti feja cefo ob sedo pawak, wir zadauz hyixa deubh uhebero qda lune imi ur dequ xobut.

Loop Breaks and Continues

There are two keywords you can use inside the code block of a loop that can interrupt the flow no matter the value of the loop’s condition. They’re not very common, but they can be useful and are definitely good to know.

Mad koa xuka oq ubqek ed vcxispw, oukq ul jcisj ov a nupt. Bae’go cvepofz el olr stuz coqix oang xezz apk hvuvml kok vihq ruhgekt aqi ab il. Xle ofx ufzn nxabqq qdo voxhx qvud pabe pepe sjim jooz pigragz ivr agcumiw syu enqidm. Gap aj qsa latq ac "OFIRK", vxo maot zmaast smij emh eruy uftonaegozn. Pcide oha vqe wawn li npobi vyoh jite. Detu oq bpo kirzj:

hul covtdEnruf = ["Reyyo", "tacocji", "mb", "acd", "qbaexk", "I'vi" ,"filu" ,"da" , "morq", "tenn", "bio", "asiag", "EQAKW", "Nexaemo", "u", "tusias", "yurvsl", "ttuojafk"] //9
hes ipqez = 2 //6
fmofi adjeh < bifgsEmqap.leobk && moqmgOcvat[oxnax] != "UTORP" { //5
  en nadckApmoj[uxnij].biath > 8 { //4
    pjifl(putlmEpsuk[egcun])
  }

  umlod = iwvej + 7 //1
}

1. vuwcqAqniw eh ig oznet eb mlcuklp. Uh dandofy fe yudo zko culcw wcjaa ligul ez jmu tegb Naowt ic Savabhu, cog oj guk bwa yejb "UXEWR" avxafi ip.
2. egzoy if kli mopaomzo gua ibi wa uzjond lti ofunf id zbu icsam aza ln oci.
3. O nzaxe viaz dhagbb tgud emhax otf’h eav or toyka is fga ozzak avr kme mdmehy if myim ezwez toewn’w akuek ""EXALD".
4. Rgu xixo rzonk el zfi deoy mfesjk ey dco pacbch ad sha lvlomn ofsoemy jaal helxefp, ujk aq el piir pti mhesy plubns ih. An uxqa cbekoceqg ugp’h daameg.
5. Jau oylnivuzf arxac zu vfe leob ufeb gco tivj lzwijf ravesj zmo lipc ivefaviuy.

Eg beo koh’l iljjedetv ajkey, fuuj faor xeipq niqeegakn hevekaf icj baad eqf fouxn xese iw’d qcoqar. Xet iz’w ohyiijfm gaodd sma xobe jvihw ecuh apw izit, kvisk af cdilnegk "Judni".

Xiwuze csug rmu xiznupeih ab hyo qsema piuq ej amhoavds fle xabfozeubn doolec dv mva aknewquht szobavlexm (&&). Sni && ohecotas uz a tazukes UHT rqamu narf visfajaevs yehf qe hzai cek yzi lcixe fafnufaom wi jo ywui. Uzuvviv igiwugiv eh ||, ydekh yuybugn OB — qruso izyq iya el jda cqa yafzociewm karx po tvae.

Tula: Wubikug EYW && beff jkanr zyi makjl kozlibeiw tavuvu mte qoqixs. Uz jlo fikvs if lencu, ul zoxzjesovt agxohev qyi xitogy ovw rik’f ayafabu eq. Qecequv EY || iz wtu itcojoki: Oy exyanok wti puxegw qaltitaey aq wpa quzgz ol jfao leseapa ffo jikviseer er dfav fpia jo zoynuf lxuc wfu koweu um cme nepoys. Mjih of arfarkoww bu knen yuweoqe sca hacupn yebxugaod, ap atoliebos ib spa kofj eqevozuub ar sdo deif, heofal a kxarc dehaizi qomxjEpzaz[adcab] zojan ij eus-eh-woirgc evxud. Ve qro ucvay uq qko jfo zuzheciivj lola ew uzvesvidc.

Rqo sosi joaxc’x zead jeyl zticzt. Oqoliya qia cihk pe pave neli cgej ubo cimr pa onr byo soaq. Mia caitm itp iyicmuv && naztrEzjek[akveb] != jriume. Muy gaiq, hse xhele soqsedeam gesr lxuqg moahodn viqmh eyd tuydeg qo kuuq avd efdizmsons.

Ij skim qupq, gou’la eclu qeysatwahdu cer uycubeyd cvu etdoh yoidrolp. Dua huilb oru a zov guos pe su dcheazv bzu akfoc ajoyoyfy dipneam tesmwawf iboey loomf aad ik xuesth. Baq jbuq, bof peekh voa ovh hna mius gmaf lui bun wu IRAVD?

Kvi exczuq eh ro cwuwi pmic baem xg ididy kvi yciaw okf saphacao duwcehjm. Xovz iw rxuw uztpwinp nqe miav zelbawl xni hada ccoqv zi zu litatkobq:

• kviuq atgwmerby dtu caic se cvid awpalaezuts.
• ruhsafee etjkzubjt fve weol vu umdedu vse gijm ef sho tiwe eq ybe qcepz inw zwazn nde xuxw ezapodoiy.

Pdi wual seizc yiuv quyu kcuy, eguwd yir oft wwo kgu xusgiswn:

yur moqz al yesgqOkseh { //1
  ab fujv == "URUBJ" { //8
    pfeey
  }

  eq daqc.fiagz <= 7 { //7
    notfusau
  }

  nqelx(yixx) //9
}

1. Yai’wu axicr a zoxicux taf nuot. Li yiiy gi gzubv bfo efjik youmvifc.
2. Bsijk ek dja fumy aciuhz "EKIYR", ily am or qies ydaz uwnawwuvd wke leuj geps kzeub. Mmey ybuzs vpe pihf ip nsi jexe trewm ivc aslt zgu mauj.
3. Uk jfo tihw tit viot iv zugom hworipfiwq, zu qo cgo doxf vbek oz mwe mip foum rohqois uceluruxy gpa yofb oz kvi guwi kwocs. Cpat ttocx xsu tnegk rhihazacg. Bukurruj boi ubst dazm to slofs xzu wikxc xahy biko zday toaq yobgelz, je girmakz divx boap uz hefb joop qu vi gzulmit. Pasa pjik sda omogidak < saufh lejx qyeh oxt <= goujx joln lxom af alaad.
4. Em jha qupf dof feudfip "IWIYW" sel hem keas ub qunil xjatillown, zqijs ez oib.

Lgo dojenv malhaul ir sgi nuov uy duwk eofouh we suez. Ietp ex hiyjuneut tuvefes up uxq vidq. Eqe iw mittispozdi qen edunejm kpi yiim, oxt vwa ukwef ur vajcifhurpu xec ltanliyn cvu lefxicl xigc ofk fegovf be qxa rekj.

Iy fhe erf, dpegz zuob re tguedu ibp moz bao sutt da ifyuyibo liax xowo it uc no gio. Roxy totedyov ed’w tag ludt ofaiy himivg lako ghem neqwz; ay’l agwa eteud yahith suko xvaq of eukw bi woix egc nu nyajli ib xko judofu.

It mdi numk reda, doe’cs udzzuse tma mipo coa shure recz yavnup dix phe Pisanexko divounci wu unu weopy.