I-JavaScript: Umsebenzi umsebenzi. Ulimi lokwakha izinhlelo JS

Imibono okuqukethwe ashukumisayo ukwakha web-IZINSIZA baye kuyinsakavukela. Amakhasi Static futhi izifanekiso Web design ekugcineni igcwaliswe ayekuthunyiwe.

Nokho, yesimanje web-isisetshenziswa akanayo ukuba emelelwa iqoqo Amakhasi eyenziwe iseva bese uvuselela isiphequluli (JS + AJAX).

Igumbi esekelwe kuwebhu okwamanje ukufika isivakashi kungaba ambalwa izihloko irekhodi, kunomunye umbhalo «ikhanda», imigqa embalwa yekhodi ku «umzimba» nazo zonke. Zonke ezinye "okukhulelwa" e inqubo isivakashi - kuba indawo enhle, noma sifisa ukuba ngomunye.

Beka incazelo kanye nohlobo imisebenzi

опыт, наработаный многими десятилетиями. I-JavaScript - kungcono emashumini isipiliyoni narabotany. It has a Umlando abalulekile yentuthuko, yesimanje ithimba afanelekayo Abadali onjiniyela. kahle ulimi ayicabangile, okuthembekile, enhle futhi ukunika ithuba wangempela konjiniyela ukubhala ikhodi for a ehloniphekile kanye self-ngcono.

Umqondo womkhosi algorithm umsebenzi lapha alikho ngokomthetho. Yiqiniso, unjiniyela kungaba noma kukuphi kukhasi ukufaka ikhodi iskripthi ukubeka kuwo futhi ngeke abulawe. страницы? Kodwa uyini iphuzu ikhodi, okuyinto uyabulawa kanye kuphela: ngenkathi kulayishwa (ukulayisha kabusha) zaleli khasi? Kungenzeka ukusetha amanani kokuqala yini ezinye eziguquguqukayo abangelutho.

Fotograf - le ndawo incazelo kwesokudla lokwehlukile nemisebenzi, kunokuba ucezu ezinhle esilotshiwe ngenxa yalo. Kuyinto iqoqo imisebenzi ebalulekile ezibalulekile, mhlawumbe - mutual uxhumano yabo ngqo, kodwa kaningi kungcono ezahlukene. incazelo Indawo umsebenzi kanye nendawo isicelo yayo akuyona into efanayo.

Akubalulekile ukuthi umsebenzi ngeke abize omunye umsebenzi ngqo, kodwa kungenziwa ngokungaqondile ngokusebenzisa kumiswa ikhodi ashukumisayo. Isivakashi ithatha isinqumo zingakapheli lekhodi futhi isebenza ngempela ezahlukene uhlelo imisebenzi.

Dynamics obusebenzayo

Functional Dynamics - akuyona kuphela hhayi bokudla kangaka eyabelwe zekhasi imisebenzi ukuthi zakha izakhi kwekhasi, nangalowo bokudla ngokushesha, futhi, ungashintsha.

Isenzo senzeka khona ekhasini, kuncike izakhi kanye isivakashi ukuziphatha kuso. Movement of the mouse, ikhibhodi, izinkinobho, ukuchofoza, izenzakalo, izinto kanye nezinye izimo eziholela kwethulwa imisebenzi edingekayo.

Ekuqaleni akukho ukuvumelana futhi akukho ngokulinganisa. Kukhona impendulo enele izenzakalo web-nsiza. Kanjani i-JavaScript okusheshayo efeza umsebenzi othile incike eziningi lobuchwepheshe (ikhompyutha, zokuxhumana imigqa) kanye semantic (logic algorithm, endaweni isihloko, okusho inkinga) izici.

Empeleni kungashiwo wagomela ukuthi into uye wasebenza okufanayo, kodwa into izovuleka ngemva okuthile, kodwa lokho okushiwo yile ekhethekile akuyona. Kubalulekile ukuthi umsebenzi-JavaScript - kuba ithuba ukudala impendulo enele izenzo isivakashi.

Lokhu Ukucabanga okusha umklamo: basakaza ukucutshungulwa ekujuleni isiphequluli olulodwa!

I-syntax ngoba eziguquguqukayo nemisebenzi

Esine-eziguquguqukayo ezibekwe umaka «iskripthi», futhi emzimbeni umsebenzi. Imisebenzi kuchazwa ngendlela efanayo. nencazelo ekhethekile ukubhala ngaphakathi umsebenzi kukhona omunye umsebenzi, kodwa kungase kudingeke ngenxa yezizathu ezihlukahlukene, futhi kuba impela ezinengqondo.

Incazelo umsebenzi ngokuvamile iqala elingukhiye «umsebenzi», kulandele igama layo, lwama-agumenti kubakaki, kuhlukaniswe ukhefane, futhi umzimba umsebenzi e besokunxele.

Kulesi sibonelo, imisebenzi ababili bachazwa ezinikeza AJAX-exchange phakathi ikhasi bese iseva. Ngokwengxenye scXHR ezichazwe ngenhla, ngoba iyatholakala kuzo zombili InitXML, futhi ngaphakathi WaitReplySC.

Igama umsebenzi futhi ipharamitha "umsebenzi"

Kukhona okuye kwachazwa version indlela lapho esine-umsebenzi umsebenzi ibizwa ngokuthi ngemva Impendulo yeseva. Ngakho, kokuthola impendulo kusuka kuseva, WaitReplySC efinyelela ithegi ikhasi, igcwalisa ulwazi wathola futhi kubangela neminye imisebenzi, okungase ukuqalisa kahle isicelo eduze iseva.

Lapha kubalulekile ukuqaphela ukuthi WaitReplySC - umsebenzi. scXHR.onreadystatechange = WaitReplySC она передается как параметр. Kodwa emgqeni scXHR.onreadystatechange = WaitReplySC uphasiswe njengoba ipharamitha. Lokhu jikelele ukudluliselwa umthetho umsebenzi neminye imisebenzi njengoba imingcele. kubakaki ezicijile futhi wabanika ipharamitha yayo (s) - umsebenzi eziyokhishwa ngokushesha. Ezixoxwa igama kuphela, kahle kakhulu lokho. umsebenzi Call uyokwenza owangena igama lakhe.

Ukusebenza lwenteke nge-AJAX, ikuvumela ukuba ushayele umsebenzi-JavaScript ngokusebenzisa idatha etholakele kusuka kuseva. Eqinisweni, ngokuthumela isicelo kuseva, omunye sici singahle neze "ukwazi" okuyinto ukusebenza uphendukela, futhi kwaba namuphi ulwazi.

umsebenzi Out yi yayo

NgoLwesine kutholakale isidumbu sendoda umsebenzi, ungakwazi ukubhala noma imiphi opharetha ulimi, ngubani, eqinisweni, ngoba kuhloswe. izici Ngaphakathi kukhona eziguquguqukayo limenyezelwe ngaphakathi nangaphandle, kodwa hhayi lezo zichazwe neminye imisebenzi.

Uma ufuna umsebenzi ukubuyela yalokho, ungasebenzisa i-JavaScript isitatimende ukubuya: ukubuya. NgoLwesine kutholakale isidumbu sendoda umsebenzi kungaba inombolo ezanele izitatimende ukubuya. Akubalulekile ukuthi bonke izobuyisa yi yohlobo olufanayo.

Ngokuvamile, onjiniyela iziqu leli thuba futhi, kuye ngokuthi isimo, unquma ukuba bahoxe ekungeneleni umsebenzi ngokushesha ngangokunokwenzeka.

Akubalulekile ukusebenzisa lonke algorithm imisebenzi, uma ungakwazi ukuphuma ngaphambili.

kwemisebenzi

Izimpikiswano ziyadlula ohlwini umsebenzi, kuhlukaniswe ukhefane, kuthiwa ebiyelwe abakaki, futhi ngemva nje igama lakhe. I-agumenti wasebenzisa amagama variable, kodwa ungakwazi kudlule amagugu ngqo. Ukuze udlulisele umsebenzi JavaScript umsebenzi, wena nje kudingeka ucacise igama layo ngaphandle kubakaki.

Ngaphakathi komsebenzi agumenti variable atholakalayo, okuyinto has a impahla obuphelele. Ungakwazi kubhekiswa kunoma yimuphi umsebenzi agumenti ngokusebenzisa agumenti [0], agumenti [1], ... ukuze agumenti zokugcina [arguments.length-1].

Ukushintsha umsebenzi agumenti ayikho ngempela ngaphakathi umsebenzi kodwa hhayi ngaphandle-ke. Ukuze ushintshe okuthile ngaphandle umsebenzi, opharetha kumele usebenzise i-JavaScript ukubuya, lapho kudlule ukubaluleka ezidingekayo ngaphandle.

Emva umsebenzi luphela, zonke elalihambisana ne kusebenta kwaso, bazobhujiswa. Phakathi sokuthi umsebenzi zingashintsha eziguquguqukayo zangaphandle, ngaphandle kwalawo zichazwe neminye imisebenzi, kuhlanganise nalezo namaphakathi nezwe.

Sine-agumenti impahla callee, okuhloswe ngalo ukubiza umsebenzi wenziwa ngesikhathi esithile. Uma imbangela ngokwayo, JavaScript nguqulo ye umsebenzi e umsebenzi uzoqalisa ukusebenza recursion.

Ukusebenzisa imisebenzi

Ukukhathazeka main imisebenzi - ukukhonza isiphequluli mcimbi. Ukuze wenze lokhu cishe njalo ithegi unekhono ucacise igama umcimbi kanye umsebenzi yokukhiqiza yayo. Ungaveza izenzakalo eziningi, kodwa umcimbi ngamunye kuboniswa umsebenzi owodwa kuphela.

Omunye umsebenzi Ungasingatha amaningi zekhasi futhi izenzakalo ezimbalwa. Ngokusebenzisa «lokhu» kukho, ungadlulisa umsebenzi ulwazi lapho ebizwa.

Ukusetshenziswa zakudala JS-imisebenzi - the bokudla umcimbi izici. Kulesi sibonelo scfWecomeGo () umsebenzi noma scfWelcomeCancel () ibizwa ngokuthi ifomu yokufaka / ekhishwa isivakashi, futhi uma kukhethwa imodi esebenzayo scfMenuItemClick (lokhu).

Kulo mBhalo, ipharamitha wadlulela «lokhu», okuvumela ukuba ufunde ngokuyisimangaliso yini diva wayebizwa. Empeleni, JavaScript ukuze qualitatively Wawufaka le-DOM, futhi ngakho sizikhandle ikuvumela ukuzulazula izakhi zawo, ukuqoqa ulwazi oludingekayo ukuthi Amakhasi Dynamics umane ube ezingalindelekile.

Umsebenzi akanayo ukubuyela yezinhlamvu, inombolo, noma omunye umsebenzi. Kungaba ibuyise umnyuziki HTML-elementi, futhi okuyinto inani elidingekayo izakhi, nge bokudla zabo, imicimbi yabo.

Ngokubeka i-elementi ekhasini, unjiniyela kudala ukusebenza okusha muhle ngokuya yokuxazulula le nkinga futhi nezimfuno zawo izivakashi, kodwa kunzima ngempela ngokuya kokusebenza.

Kusukela intuthuko enjalo olusebenza ngokugcwele, okulula ulahleke ikhodi bomdabu, kumsebenzi izingcingo, e izikhathi lapho kwakhiwa noma ukuthi okuqukethwe eyodwa noma enye kwekhasi. Ngaphambi kokuthatha siqondiso yentuthuko, hhayi angakwazi nesisindo kahle konke.

On ukusatshalaliswa ukucabanga

Umthuthukisi has ukucabanga ezingeni tonkhe tincenye ikhasi, ngaso sonke imicimbi, futhi abe isethulo esicacile sendlela konke empeleni kwenzeka. Kunzima, kodwa umsebenzi kuwufanele.

Ngo-JavaScript, umsebenzi kungenzeka imisiwe ize ezinye umcimbi, futhi izici ezifana zande, kanye nemicimbi ukuthambekela ukusakaza singene "ihogela ukubonakala" we izilimi ezihlukahlukene.

Kulesi sibonelo, endaweni ethile ngaphambi umsebenzi abizwa ekuso, okuyinto okuqalwe into ifayela imenyu. Kusolwa lokuvula, okungukuthi ewindini amafayela eziyisikhombisa nje, ezingasetshenziswa zisuswe futhi lusetshenziswe. Zingasuswa njengoba ifayela ngokuchofoza irowu, futhi imicibisholo kanye amabhlogo lemigqa eziyisikhombisa.

Esimweni ngasinye has lwenza umsebenzi walo ohlukile. Ngamanye amazwi, kulesi sibonelo elula, udinga ukubhala ambalwa eziningi izici bayosabela kanjani lapho izenzakalo ezihlukahlukene, futhi abanye balaba imisebenzi uyozisingatha ezihlukahlukene ongakhetha kanye izimo izenzakalo okungezona ezakhe.

Ngokwesibonelo, lapho kokukhipha sendaba kumele dengwane upwardly. Lokhu kuzodinga noma wenze ukukhetha omusha kuyinsakavukela futhi ngokucacile umthombo, noma ukubala imigqa, sebenzisa umsebenzi JavaScript ku array futhi ingafika eqophelweni nenhle.

I-agumenti futhi imiphumela imisebenzi

I-JavaScript ikuvumela ukuletha ikhodi isimo "efakiwe ngokugcwele". Ngokuvamile, lapho i-agumenti komsebenzi umsebenzi. inketho Kuvumelekile, umsebenzi ibuyisa umsebenzi. I-JavaScript alithathe ngempela ngomoya ophansi.

Lena indlela enhle, kodwa kunalokho kuyinkimbinkimbi maqondana nokusetshenziswa. Ngokomthetho kuvunyelwe wokufihla ukunikeza "obusebenzayo" ukuhamba logic kuphela umthuthukisi oqeqeshiwe.

Lapho umsebenzi JavaScript umsebenzi - konke kulungile, kodwa lapho umsebenzi yakha umsebenzi, nokuthi elinye, logic kunzima ngempela ukulandela. Eqinisweni, umbuzo akufanele ube ukuthi ukusebenzisa amakhono, umbuzo uwukuthi ukuthola yi ephephile futhi zilungile.

ukunakekelwa Unjiniyela kucacile futhi kulula. Kunenkinga, udinga isixazululo, hhayi bug like «-JavaScript iphutha ukusebenza okungavikelekile» , isikrini ingenalutho, noma ayeke zonke injini isiphequluli.

Uma i-agumenti umsebenzi, khona-ke unjiniyela kudlule kwenombolo nge anezakhi ezikhethekile, ukuthi akuyona inombolo, hhayi intambo, into. Kodwa ukusetshenziswa ukucabanga kanjalo kuphakamisa imibuzo kungaholela yokuthi ukushintsha eziguquguqukayo yangaphandle futhi umphumela ukubulawa umsebenzi. Kuye izinguquko kuyoba ezanele adlulisiwe.

Ukubulawa ikhodi

Ukuqalisa ikhodi ukubulawa ekhiqizwa ngokuhamba umsebenzi enye ikhodi, kungenzeka esebenzisa «eval». It is hhayi ibhekwa isixazululo kakhulu, kodwa ngokuvamile siyehluleka ukuthatha izinkinga ikhodi imisebenzi ezingadingekile, futhi ukuthi ubeke umkhawulo kumiswa umugqa eziwubala of-JavaScript ikhodi bese umane akhiphe ke.

Kulesi sibonelo, kwakheka Faka Stitch ku div operable olunye ulwazi. Diva nokuqukethwe ulwazi inombolo ezahlukene izikhundla ezahlukene, ngoba isinqumo esinjalo kulesi simo akayinekezi isimo yibhange «javascript iphutha ukusebenza okungavikelekile» , kodwa ngokuqinile ukunikeza umphumela oyifunayo.

Imininingwane ehilelekile-JavaScript Paradigm shift "umsebenzi e umsebenzi"

Uma ungenza ngaphandle frills, kungcono ukuyisebenzisa. Kuzo zonke izinkethi zinhle. Yiqiniso, ezimweni eziningi, kuba ikhambi kuphela.

Isibonelo Classic of recursion: ifakthoriyali. Kunzima ngokwanele ukubhala algorithm ngeke iluphu, kodwa silula, ungakwazi ibenze amanani imvilophi. Ngokwesimo kukhula ngokushesha kakhulu.

Nokho, recursion, futhi umsebenzi ubiza omunye umsebenzi, okuyinto engenza-callback unolwazi - izinto ezivamile.

Ngokwesibonelo, itafula elivamile. Enye ithebula kungenzeka itafula. Lokushutheka ayikwazi ishintshela kokungavinjelwe. Bhala lamatafula awayo izici - okunethezeka kakhulu.

Izibonelo ezinjalo baningi, futhi konke lokhu ngeke kube inkinga yangempela futhi ukuphokophela, hhayi ngenxa izinhlelo. Yingakho le nkinga itholakala lokuthi ukuthi-no-frills musa emisa isimiso imisebenzi, ngokunembile, ilungise inkinga yayo kanye nokusebenza okwalandela okunokwethenjelwa iba i-JavaScript ukunakekelwa, futhi kanjiniyela.