I-JavaScript: typeof - isidingo noma ithuba

Kukhona sebenzisa be uhlobo oluthile idatha, kanye wayenesithakazelo ukucubungula kwabo ukuze bathole umphumela. I ukubusa "imibono atypical e izincazelo" iyakufika ngokuzumayo, kodwa ngokwemvelo. isimemezelo Oku-variable akuseyona impoqo, futhi likhomba uhlobo yayo jikelele ilahlekelwe yonke incazelo, okungenani i operation lapho khona uhlanganyela.

Unicode likwazi ukuboshwa nokuqaqwa izandla zakhe: akudingekile ukuba ngimemezele into ekuqaleni. ngesikhathi ukusetshenziswa Ngokuvamile kuphela abazokwazi ukunquma ukuthi yini ukuthatha, yini okufanele uyenze futhi kanjani. Ngokuqondene izinhlobo, bona ngokwabo "ziye zaba amanani," okusho ukuthi, kuba idatha ephinde ixhomeke entweni!

It has noma akanalo, kahle, pho kunani?

Incazelo lesilula variable "aaa" futhi algorithm etholakalayo ukucutshungulwa:

aaa ; var aaa;

( aaa ) { uma (aaa) {
= 'I am!' Res = 'mina!' ; // NGINGUYE!
{ } Else {
= 'me no...' ; Res = 'kimi kungekho ...'; // Anginayo
}

Inikeza yalokho ecacile: ". Angithembi" Lapha ukubaluleka umsebenzi-JavaScript typeof = esingachaziwe. Vele uchaze variable - "kokungenzi lutho" akusho. Yiqiniso, lapho aaa = 1, sithola: 'Mina ngiyindlela, kodwa uma aaa = 0, ukuthi kuyoba njani esimweni sokuqala: "Angithembi ...." logic Omangalisayo, isazi sezibalo, kanye isakhamuzi elula, futhi wahluleka ucabange ukuthi ukubaluleka zero has libe nencazelo ehluke kakhulu kunaleyo zangempela. yesimanje (atypical) izinhlelo kuphela okwazi imibono enjalo kwakwakhiwa!

I-JavaScript Design typeof, kanye inkulumo ezihlakaniphile uma (aaa) {... x ...} enye {... y ...}, ine omuhle kakhulu izimfanelo umthengi futhi elula kakhulu ukusebenzisa.

On izici of Cyrillic futhi amagama Latin

uMklami Professional uyohlale uthanda i-English ngokudweba izinhlamvu isiRashiya, sibonga ngobuqotho isigaba izinhlelo zentuthuko, lapho abanye expanses cybernetics ayaziwangwa, kodwa kwezinye izindawo computer science waya kancane kancane ekukhuphukeni. Saqala ukuba azale ande ukuthuthukisa izilimi uHlelo, esekelwe syntax 26 izinhlamvu zamagama kanye nesethi nezinye izimpawu ezivamile.

I elula kunazo futhi zemvelo kwaba ikhodi bomdabu, babuphelele, ephelele, kodwa sicaciselwe izakhiwo ngamunye, nezilimi ephezulu ezingeni umqondo ukuthwala yonkana architectures ngokushesha kwaphuthuma. Lokhu kuphambana kakhulu okwamanje wamanje: ngezizathu Analogue-JavaScript typeof = esingachaziwe | yezinhlamvu | inombolo | eziphusile | uphikisana | umsebenzi uma kwakungeyona elula. Zonke izilimi babe ngokuqinile esisemthethweni, abe-syntax esiqinile futhi ugweme ukungaqiniseki.

Izinhlobo, eziguquguqukayo, kanye nokusetshenziswa yabo

Point kubaluleke kakhulu. Ukuthayipha nencazelo eziguquguqukayo - ingxenye ebaluleke kakhulu ohlelweni, uMklami awukwazi ukubhala algorithm ukusebenza, kuyilapho singahlangabezani ukwehluka wangempela idatha esiqinile esisemthethweni isithombe lokwehlukile, afanayo, izinhloso kanye nemisebenzi.

I-JavaScript lubekezelela zonke zanqwabelana engaphezu kwamashumi wamandla obusebenzayo, yonke imiklamo zakhe ezibonisa ngokuphelele ukuqonda samanje syntax kanye nemithetho efanele sibekwa engasho lutho yakhe.

Umbuzo uwukuthi, uma lokhu kufanele kwenziwe uma kubalulekile ukuchaza luhlobo lwetheksthi, i-JavaScript typeof umsebenzi. Empeleni ongakhetha friendly uthayiphe umbhalo kancane: string uhlamvu nenombolo. Nokho, indima into umbhalo Ungadlala, ngisho amalungu afanayo design array.join (), okuyinto uxhuma zonke izakhi ku embhalweni owodwa, okungukuthi, e umugqa owodwa.

isitatimende banal: nxazonke kukhona lwetheksthi kanye ne-JavaScript typeof umsebenzi kumele kube ngesikhathi esifanele ukwenza oyifunayo Wemiqulu. Lokhu kuyiqiniso, kodwa umkhuba kuvela ngenye indlela. Into ye-JavaScript typeof uyonika ukubaluleka efanayo kuzo zonke izimo ezintathu:

aaa = {}; var aaa = {};
= typeof ( aaa ); Res = typeof (aaa);
+= '/' + typeof window . Res + = '/' + typeof iwindi. ; idokhumenti;
+= '/' + typeof ( document . forms [ 0 ]); Res + = '/' + typeof (idokhumenti amafomu [ 0]).

Imiphumela: into / into / into

Ukusebenzisa kungenziwa typeof (aaa) kanye typeof aaa format umculo - akusiyo kubalulekile, kodwa kuzo zonke lezo zimo Impendulo inikezwa, kodwa ngokuphelele akusho lutho!

Ukungaqiniseki iba ngokuqiniseka

izici Ukuhlela ebudlelwaneni eyinqaba: it is flying ngakho phambili ukuthi ukunyakaza esikalini njalo uyanda. Ukulandisa kuqhubeka izinyanga, amasonto noma izinsuku, ngezinye izikhathi ngisho namahora. Imisebenzi ethile Dynamics kumiswa algorithm ukuxazulula enjalo omatasatasa futhi kuyakhandla ku ngokuqhubeka ukuthi Unicode ukusebenza ngaphandle uhulumeni angakwazi wenqabe isinqumo ngosuku, isonto noma ngaphezulu.

isixazululo Yemvelo-JavaScript typeof kanye umkhuba lwezinhlelo into-ngamakhasimende, okuyinto kule kwemavi uhlukile owandile izilimi eduze yesimanje, usekhuluma maphakathi gravity entweni. iphuzu ezimangalisayo kakhulu: ulimi iba ukwakha ehlanganisa engasho lutho, kunokuba iqoqo imithetho syntactic.

Simple nedatha akudingeki ukucacisa uhlobo yayo, noma kunalokho ukusetshenziswa i-JavaScript typeof ngokwanele. Uma kudingekile, isikhathi sokusebenza enakekela kugucuka ezifanele, kodwa i-JavaScript typeof into unikeza impendulo enengqondo kunazo zonke iwukuthi into futhi uhlobo lwenkinga - ukukhathalela kwakhe! Lokhu logic for the imibono classical mayelana uHlelo nzima lizwakale, kodwa ukuthi sinjani ngempela isimo izinto ezilungile.

Uyabakhathalela luhlobo - ukucacisa uhlobo yayo, ukubonisa izakhiwo zabo nokwenza izindlela zabo. UHlelo ukuze bathuthukise-syntax senu nakho konke ngomzuzwanyana usekhuluma maphakathi yesisindo syntax ezakhiwe uMklami engasho lutho: uhlelo lwayo lezinto ukuthi zuku.