JavaScript iziporo: kuba, lo gama, wenze-ngoxa

Imbali ukuyilwa mihla zombuzo ulwimi lokuprograma iyafana inkqubo lolwazi iphela. Kwaye ukuba ekuqalekeni ... Kodwa ngoku yonke into ilula nefikelelekayo.

I algorithm ekugqibeleni - kusoloko nomxokelelwane mbali imithetho. Okukhona in senkqubo - kanye landelanisa zidityanisiwe. robin Round akuzange ebonakalayo ikhonkco umyalelo lezibuko okanye ukufana. Labels, uhambo, kunye neemeko - ngokwaneleyo nje nasiphi na isisombululo. iilwimi ezisebenzayo ziye ndayihluthwa ukubaluleka ezi zimvo, kodwa kwafuneka ukuba ukuphinda amacandelo ikhowudi wahlala.

Ibhrawuza: DOM, ulwimi lwakhe + server

JavaScript-imijikelo ahlale, nangona iingcamango ezisebenzayo ufumene intsingiselo ekhethekileyo. Mhlawumbi into eseleyo of "Isixhobo SokufundaName" yaye "Isandulela", kodwa ke okona kubalulekileyo, indawo apho ahlala i JavaScript, kwakhokelela yokuba kukho, kodwa kusenokwenzeka ukuba esi sigqibo yakutshanje.

JavaScript ubaleka ngaphakathi ngebhrawuza ufumana iphepha, parses ube DOM kwaye luqalisa nephepha leempendulo lokuqala. Onke amanye amaphepha, kubandakanywa ilandelwe kule - ke umbhekisi phambili kwezandla balawula ulwimi ngayo ikhowudi kumncedisi kwaye bafumane iziphumo usebenzisa Ajax mechanism Ingabizwa.

Umkhangeli owenza ukufumana JavaScript-ikhowudi ukuba bangasebenzisa izinto ibrawuza, kuquka lowo lokudlulisa kumncedisi kwaye ufumane impendulo, njengoko leyo inokufana i HTML-lophawulo kunye nezimbo kunye nekhowudi actual. Impendulo angamelwa kwimiboniso kunye izinto. Bonse ukusebenzisa i JavaScript imijikelo elahlekileyo, amathuba ziphuphumela ukuyenza ngaphandle kwabo, kwaye ukubeka isikhangeli yokuxhoma ezilandelanayo olungenasiphelo imithetho akukho sisombululo engcono.

Eneneni amasango zikhona ezininzi lwesivakalisi JavaScript, abaphuhlisi angaba uyilo eqhelekileyo imisebenzi yabo.

JavaScript ikhowudi isikhundla isithuba

umdwelisi nkqubo Modern azithethi ukuba wasebenzisa umjikelo (kuba, Lo gama, wenze Lo gama, ...) - ekugqibeleni uthotho imijikelo (imijikelo) iprosesa, ulandelelwano olulula imisebenzi yokubini, zokubala ekuhloleni waphazamiseka, ie iimeko.

Ngenxa yoko, umjikelo ayikho kwinqanaba lolwimi machine: ludibaniso imithetho yesiqhelo, imisebenzi enemiqathango kunye nokuguqulwa. Level phezulu, enoba oko kuthetha ukuba zingasetyenziswa uphuhliso ibrawuza Interpreter JavaScript, imijikelo iya kuba sisiganeko esahlukileyo. Yaye "amaqhekeza ikhowudi" iya kwenziwa ngamaxesha ahlukeneyo kunye izizukulwana ezahlukeneyo badwelisi benkqubo. Umgangatho ngasentla "ukwakha» JavaScript. Le syntax nelinika mijikelo mihla JavaScript.

JS - ulwimi entle: esebenzayo, mihla ze-mvo ngokupheleleyo. Syntax yesi sixhobo liquka zonke zilungiso ukuba uluphumelele uvavanyo kwexesha waba isiseko nayiphi algorithm lecebo. Kodwa ke ngenxa yokuba imijikelo ukuba kuyimfuneko, ngokwenene? Inkqubela kweenkqubo imibuzo zohlobo esisiseko wayesoloko ebuza ngokwam, kodwa kwezinye iimeko, ukufumana isisombululo.

zizathu Injongo

Umjikelo babe babini kuphela ezahlukeneyo imeko okanye counter, kodwa eneneni (kwelona nqanaba lisezantsi) nawuphi na umjikelo - kuphela hypothesis. Kwezinye iilwimi umjikelo eqhelekileyo "ngasinye." In JavaScript Isakhiwo imijikelo foreach emelwe ipropu entweni, kodwa unako ukusebenzisa uhlobo array.forEach (...).

Kuyo nayiphi na imeko, ezimbini iinketho: ikhowudi umatshini ukuba umenzi ekugqibeleni zonke algorithms lwenkqubo, uze usibhale kwiilwimi yokutolika, akukho ezinye iinketho umyalelo chain Phinda: ukuze abe nento yokwenza kwakhona de:

• ukubalwa counter;
• de imeko uzalisekisiwe.

JavaScript - itoliki eqhelekileyo. phawu ezahlukileyo: esebenza ngaphakathi isikhangeli isebenzisa izinto zayo likuvumela ukuba wenze ubuchule kwicala lomxhasi njengoko imithwalo iphepha kwi umkhangeli zincwadi, kwaye ngethuba umsebenzi wayo.

Simple umjikelezo ngalinye

Ngomhla foreach JavaScript ephambuka khangela ngathi ukusetyenziswa kwemisebenzi afanayo:

Ukusetyenziswa imijikelo ezinjalo musa kunokubangela iingxaki. Ngokusemthethweni, akukho umjikelo ngqo. Kukho umsebenzi impatho efanayo iziqalelo uluhlu.

Cycle ekhawuntareni

Okunye baqhele ukujonga imijikelo JavaScript ukuba:

Apha, counter lenza umahluko ogama value bahluka nendlela phawu ekupheleni imeko komjikelo. Akunjalo wokubala nemeko iquka umjikelo variable. Kodwa kolawulo isiphelo indawo kumjikelo ixhomekeke ngokupheleleyo umxholo zabo.

emphethweni olunemiqathango

Option ne gama JavaScript inika, kuxhomekeke xa ufuna ukukhangela le meko. Ukuba umzimba yomtya kusenokungabi zibulawe nakanye - lo, ukuba umzimba kufanele kwenziwe ubuncinane kanye, yinto enye;

Kwimeko yokuqala, ukutolika lo gama yoyilo, JavaScript kuqala lijonga imeko, yaye ukuba iyinene, isebenzise loop. Kwimeko yesibini kumjikelo iya kuqala kubulawa. Ukuba iziphumo yezahlukileyo ecaciswe izakhiwo enikiweyo ukwenza gama, kuya kuthatha ixabiso lobuxoki, yomtya oyekayo.

imidibaniso Kuku of ubuchule ezilula

Umsebenzi ophambili (inxalenye) nawuphi algorithm - ukufumana, uze kuphela wenze isigqibo malunga ntoni elandelayo. Eyona abangekaphuhli ukhetho Uphendlo - isibheno variable, imiphumo iba ngokukhawuleza. Ukuba yezahlukileyo baninzi, yaye unemilinganiselo ezininzi (uluhlu), ngoko ke amaxabiso isampuli kufuneka lufumanise ukuba uya kuqinisekisa ukuziphatha elizayo leempendulo.

Le mfundiso elula wenza ndzhendzheleko ikhawuntala kwi JavaScript uhlobo ulwimi ilikhubalo lokunyanga zonke iingxaki. iikhompyutha Modern isantya ezahlukeneyo. Ixesha ukuphumeza zeempendulo isikhangeli ngokwaneleyo, akukho ukungxama. Kulula ukuba lize kugxothela into ethile. Ngenxa yoko, J avaScript for ephambuka zithandwa kakhulu.

Olubi kulo hlobo nto. Kodwa emva le ndlela kulula ukuphulukana kakuhle apho omnye okanye omnye algorithm ebhaliweyo. Aba ezingenamsebenzi. Konke oko kubhaliweyo, nayiphi na inkqubo oko utsho yenza ucacelwa. ukutya kakhulu kwi imijikelo J avaScript ngenxa, umphuhlisi akakwazi ukubona kakuhle eli lungelo kwaye ukudala algorithm eyaneleyo.

Ukusebenza, enye imbonakaliso ezikhona

однотипного кода можно представить функциями - алгоритм сразу преобразится, основное тело скрипта уменьшится в размере, все станет читаемым и понятным. Ukusebenzisa i JavaScript-imijikelo, imizekelo zohlobo olufanayo ikhowudi kumela imisebenzi - le algorithm kanye similise, umzimba engundoqo elishicilelwe zancitshiswa ubukhulu, bonke baya kuba efundekayo noluqondakalayo.

Oku isisombululo ngokupheleleyo entsha, kodwa eneneni asikuko ngaphaya kwemida kwezinye owakha zolwimi. Ngokukodwa, J avaScript imijikelo zingafumaneka split lwamandulo () umsebenzi:

cResult = '9,8,7,6,5,4' ; var cResult = '9,8,7,6,5,4';
aResult = cResult . var aResult = cResult. ( ',' ); yahlula ( ',');

Akukho umjikelo, kodwa ngenye wenza lo msebenzi, ukuba kungabi ngokukhangela uphawu '' uze usebenzise yona ukwahlula inombolo omnye komnye.

Ukutsala kuyo kuphunyezwa ngayo phakathi ukwahlulwa () msebenzi kumana kunye nokusebenza kwayo JavaScript usebenzisa yemijikelo ngokwemiqathango yokusetyenziswa - lula ngakumbi. Kuyimfuneko ukuba indlela enjalo kukhokelela kuphuhliso kusebenza umsebenzi ngamnye, ngokulandelelanayo, kodwa iyonke noko ukuba kule ndlela.

Le misebenzi allt (), padc (), padl () kunye padr () - into ayikho kwi JavaScript, kodwa ke ngamanye amaxesha kuyimfuneko ukuba asuse umtya okanye izithuba ukulungelelanisa ubude bomtya ukuya ekhohlo, ekunene okanye kumacala omabini. Umzimba le misebenzi - JavaScript-mijikelo. Simple, ifikeleleke kwaye ungaze akuxhome algorithm awasebenzisa ngayo.

inani Embodiments ukuguqulwa imisebenzi qibo-16 yokubala we-10 yaye emva inkqubo, kulula ukuba ukuxelela data ukusuka kwenye format ukuya kwenye, kwakheka apha do a ngelixa imijikelo. compact kakhulu ngempumelelo kwezivakalisi.

imijikelo ezichanekileyo - ukumelwa ezikhona

JavaScript - singafani nezinye iilwimi kweenkqubo kunye iintlobo ezahlukeneyo kwiinguqulelo, kwaye okona kubaluleke kakhulu, idla ukuba ukutshintsha lwesivakalisi, kunye ukuphuhlisa nokwandisa ngayo.

Umdwelisi nkqubo ecinga usebenzisa JS, loo iyahluka ukusuka PHP umdwelisi nkqubo yokucinga (ngakumbi, kunye nezinye iilwimi xa iyonke, ngokunjalo, ngaphandle ukuba i "Isandulela 'kunye nabalandeli bakhe zingafakwanga kwicala ngokubanzi), xa algorithm ayiphelelanga eziguquguqukayo, kwimiboniso, abanini sabelo, izakhiwo elibujikele .

Ukuba simele sicinge ukuba akukho imijikelo, nokusombulula ingxaki kuyimfuneko, ndlela ilula (ndivalwe) - zibonisa ukuba inkqubo data yokwenza, ezo ingongoma okanye iingongoma inkqubo kwisithuba ulwazi. Yintoni ingongoma noko inkqubo amanqaku - yinto kwisifundo esithile. Kuba uhlelo, le ithisisi uthetha: a elula, oku isethi data ezilula. Ngokwendalo, oku elula elinye inqanaba ukuya kwinqanaba ngezantsi inkqubo iya kuba, kodwa kwinqanaba eliphezulu - ingongoma.

Ngale ndlela, kwinqanaba ukhathalelo - ukubonisa bangoobani ngokusebenzisa iindlela zabo. Xa ndawana super-nkqubo, umsebenzi kwenkqubo - ukubonisa umongo walo kudityaniswe lwamaqumrhu akwi amanqaku ayo.

Le ndlela endala ingcamango kweelwimi lwenkqubo, kodwa sekunjalo akazange wafumana ukubonakaliswa kwayo aboneleyo kweenkqubo. badwelisi benkqubo abaninzi bacinga ngokuchanekileyo, kodwa ngenxa yomsebenzi wabo amagqabi kangako.

Kuluncedo amaxesha ukunxiba ngokubopha iqhiya emehlweni akhe ukubona ihlabathi!