JavaScript Zungulirani kupulumutsa mopanda malire zosintha

JavaScript - chinenero cha osatsegula, chifukwa aliyense vuto amafuna zosintha yake, magulu ndi zinthu. Nthawi zambiri yokwanira kugwiritsa ntchito basi ufumu (choyenera chinthu Model). Koma ngakhale ngati milandu, zolondola ponena za deta ntchito nthawi zonse kumathandiza pulogalamu wangwiro, yosavuta kugwiritsa ntchito ndipo anayamba kuukonza.

Mawu n'zofunika, koma, kunena za pulogalamu kuti kuyigwiritsa ntchito ndi kusintha, n'koyenera malire "deta" mawu ndi "zosintha". O ndi zimene iwo adzakhala - JavaScript Zungulirani, chinthu, kapena inteja - zimadalira vuto, kapena m'malo ku malo makamaka mu izo.

kachidindo logic ndi deta

Mapulogalamu ntchito kusintha deta. Panali ena zosintha zosiyanasiyana za zithunzi (mizere, zizindikiro, manambala, masiku, ...), monga ulamuliro, magulu payokha pabwino, ndipo (banjali lotsiriza la zaka) zinthu.

Panthawi ina mu nthawi okhwima deta kalembedwe wakhala chidina, ndipo tsopano mu chinenero chirichonse masiku ano, zimenezi kusintha osati okhutira komanso mtundu. Zabwino kapena zoipa, zidzakhala zowoneka, koma amphamvu kalembedwe lili ndi zinthu zake zabwino. Komabe, ngati izo zinachitika, ndiye bwanji "rastipirovat" dongosolo lonse?

Kumbali zamalankhulidwe, mwachitsanzo kunja malembedwe a, variable aliyense ali ndi phindu. Ndipo izo ziri mu boma lililonse la zochitika zikusintha. The ndondomeko ya kusintha - ndi kuchuluka kuti, mwa mawu a JavaScript - mchitidwe zosiyanasiyana.

Mu zina mawu, ngati mapulogalamu waganiza kunyoza mtundu wa variable ndi kuika mu chinenero cha nkhawa yake yake kutembenuka kwa mitundu, bwanji Chepetsani: Pali chabe deta bwino, Mulekeni chomwe iwo ali pa nsonga ya ntchito - ndi chiwerengero, zingwe, khamu, kapena sakugwirizana - ndicho malamulo kuthetsawo. More molondola: uyu ayenera yokha kudziwa zimene mungachite ndi izo ndi momwe.

Zambiri deta ndiponso malembedwe

Zambiri zosintha ndi mitundu yosiyanasiyana. Mtundu kutembenuza zichitidwa basi pakakhala chosowa.

Mwachitsanzo umu ndi variable m ophweka, pamene chifukwa adzakhala anapanga ndi JavaScript Zungulirani aCheck. I variable akufotokozedwa mwachindunji mu ntchito mkombero aCheck. Apa, khamu zinthu (analengedwa ntchito Zungulirani kukankha JavaScript dongosolo) amaimira mfundo zitatu za mitundu yosiyanasiyana. Iwo zotuluka kayendedwe ka woyamba mu mzere m dzina mtundu, wachiwiri - mfundo zenizeni. Mtundu kutembenuka basi.

Za chiwerengero cha zinthu mu magulu

The JavaScript Zungulirani si osiyanasiyana associative. Accesses zinthu pogwiritsa ntchito makiyi n'zosangalatsa kumva, nambala pazipita zinthu - 2 ^32, koma kuyesa kuchepetsa chiwerengero cha zinthu sayenera.

aligorivimu zabwino nthawi zonse lowonekeratu chiwerengero Dunn ndi JavaSscript Zungulirani kutalika kapangidwe koyamba malembedwe si kulamulira buku la zosiyanasiyana pa nkhani ya nkhani zake.

aCheck.length mtengo si nthawi zonse chiwerengero cha zinthu. The JavaScript Zungulirani akhoza muli ochuluka ndi kuti pali watumidwa, koma kupeza mmene nthawi zina inu kuchita khama.

Mu chitsanzo ichi aCheck mawu [5] kumawonjezera kuti zinthu zisanu zosiyanasiyana. Kuyamwitsa chiyembekezo kuti kutalika Mbali adzakupatsani mtengo wa 4, sayesedwa wolungama.

magulu associative

Yokhala JavaScript Zungulirani zitha kukhala wamba, ndiko kuti, zinthu ndi kufika ndi n'zosangalatsa kumva index. Koma kunena zoona, mungathe kugwiritsa ntchito mfundo associative.

ntchito yosavuta ndi zopanda phindu kusanja mizere ya mizati tebulo akhoza kuthetsa zosiyanasiyana associative. Point mu bwalo pafupi ndi dzina la ndime kumabweretsa palibe kusanja, mpaka muvi - atsikira, pansi muvi - m'mwamba. Dinani pa mavuto ndime (realiatsii gawo pa JavaScript: Sanjani Zungulirani).

Mu chitsanzo ichi osiyanasiyana kwaiye cSortCols kusanja malo mwa pagawo lililonse makamaka (S, C, W, ...). Makhalidwe malangizo u yekha, d. Pulani onse ligated mu mzere womwewo (ndime code, ndi kusankha malangizo). Zimenezi amayang'ana pa mbali zonse za zosiyanasiyana, ndipo gwiritsani ntchito JavaScript Zungulirani kutalika ntchito Sikuti.

Kupanga ndi khamu kusanja mu JavaScript

Wokongola zinachitikira - kulemba 'var xMass = []; kapena 'var yArr = {};'. Mbali yoyamba, zosiyanasiyana mwachizolowezi kudzayesedwa, ngati chachiwiri - associative. Ntchito njira JavaScript Chatsopano Zungulirani () ndi zotheka, koma zambiri dongosolo lino ntchito pa zolinga zina, makamaka kugwira ntchito ndi zinthu.

Pangani mizere, inu athanso mudzaze dziko zosintha, koma monga ulamuliro, kudzazidwa ndi yeniyeni zikugwira ntchito zosiyanasiyana pompopompo, pa kuphedwa kwa mwambowu. Ngati ndi kotheka, mungathe kugwiritsa ntchito kusanja JavaScript Mtundu Zungulirani mamangidwe omwe si kusintha kwambiri, koma limakupatsani kulamulira ndondomeko kudzera mwa ntchito zake.

Kuitanira arr.sort () kumayambitsa kusanja matebulo mu ASCII otchulidwa zotsatirazi ndondomeko. The osiyanitsidwa ntchito - zinthu reshuffle: arr.reverse (). Ntchito kumasintha dongosolo la zinthu zina zosiyanasiyana pa n'zosiyana ndi.

Nthawi zonse, mawu amatanthauza zosiyanasiyana arr. Mbali yoyamba kuloledwa ntchito kusanja awo ntchito, kuti ndi vuto arr.sort (myfunc (a, b)) chingandithandize kuyitana kwa mwini myfuct ntchito yanu, amene ayenera kupereka zotsatira malingana deta: a ndi b. Ngati zakale ndi zosakwana wachiwiri, ndiye -1 ngati mwake, ndiye 1, ndipo ngati = b, ndiye 0. Apa, muyezo poyerekeza anatsimikiza ngati ntchito ya mapulogalamu myfunc.

Ganizo amafotokozera yogwira

Chithunzichi kuitana mu ndondomeko kusanja, angachichite zochita zosiyana. Kwa mamangidwe omwe amagwiritsa, si lamulo kuti ayankhe magawo athandizira, ndi chifukwa - osati manambala atatu 1, 1 ndi 0 mwa dongosolo lomenyera pokhala ntchito cyclically kuti zinthu zonse, mwina musanjenso zosiyanasiyana.

Ngati ife tiyerekeze kuti khamu - ndiwo kuopa ena, ndi zina dongosolo deta, ndiye JavaScript Zungulirani ali n'kukhala zili variable wa variable lapansi.

Ngati ife monga maziko ntchito woyamba kapena chinthu chotsiriza cha khamu okhutira ake, chilango cha ntchito mtundu angathe kutembenuza osiyanasiyana moti woyamba / mchitidwe omalizira adzakhala osiyana mogwirizana ndi zikhalidwe za vutolo.

Mfundo imeneyi angalole njira redesign aligorivimu Motero, makamaka, kuti sipafunika yaitali ntchito zojambula ngati () {} wina {} ndi magetsi () {choncho '' ...; choncho '' ...; ...}.

Ndi zikugwira ntchito zili zosiyanasiyana, mukhoza kusuntha zinthu mkati mwake, potero kusintha kunja magwiridwe, amene akhoza zopezera loyamba kapena otsiriza amafotokozera.

JavaScript Zungulirani: ntchito n'kosathandiza

Manenedwe ndi zabwino chifukwa timatha inu osati kusintha kapangidwe ndi ochititsa deta, koma malamulo enieni. Lingaliro la kulingalira variable monga abstraction ndi mwachitsanzo, poyamba popanda kupereka udindo wake generic, kutsegula M'maso latsopano.

Kuyambira ndi abstraction, variable, khamu kapena chinthu amakulolani kugonjera deta processing ngati ntchito deta izi, ndi mphamvu.

Mwachitsanzo, kuwerenga lemba, tingathe kufotokoza izi "mawu", umene unagawika mwatsatanetsatane - mayeso a "mfundo" (mu nkhani, komwe ndi kutenga nkhani malembedwe a ziganizo). Bwana lidzasweka pansi mu mawu (mu nkhani, koma ndi malembedwe yoyenera). More mawu ndiponso makalata.

Zotsatira: mukhoza ntchito pa mlingo malemba, ziganizo, mawu. Pa mulingo uliwose, inu mukhoza kulenga ntchito "wapadera" amene amafuna ofanana kapena analogous. Inu mukhoza kulenga ntchito ya ntchito ziganizo, mawu kwa deta zina.

Modern mapulogalamu kwa nthawi yaitali si mbalume, koma kuti pa zaka khumi zapitazi mwa dongosolo syntactic ndipo zimene anatsegula M'maso watsopano kutukula zinenero posakonzekera - koma kuti anapeza ndi ntchito.