JavaScript: basa ushande. Zvirongwa mutauro JS

Ideas simba tigutsikane kuumba web-UPFUMI vava vasingambooni chakaipa nazvo. Kunofambira mberi mapeji uye templates Web Design pakupedzisira vapedza basa ravo.

Zvisinei, ano web-zvekuvaka hazvirevi kuti hunomiririrwa chine mapeji vanowanika nokuda server avezve Browser (JS + AJAX).

Web-inobva dzigare mairi panguva yokusvika mueni kunogona kuva nemudzimai kwemazita nokuti zvinyorwa, vamwe rugwaro ari «musoro», vashoma mitsetse bumbiro iri «muviri» uye zvose. Vamwe "mimba" iri nedanho mushanyi - chiri yakanaka nzvimbo, kana vanoda kuva mumwe.

Uise tsananguro uye hunhu mashandiro

опыт, наработаный многими десятилетиями. JavaScript - zviri chiitiko narabotany emakore. It ane nhoroondo chinokosha okukura, ano chikwata vanokwanisa creators Developers. Language zvakanaka vakafunga panze, yakavimbika, akanaka uye rinopa mukana chaicho Developers kunyora bumbiro kuti kwaye uye kuzvidzora kuvandudzika.

Pfungwa imwe algorithm ari basa pano hakuwaniki pfungwa. Chokwadi, yokuvaka anogona pose papeji pinza manyorero remitemo kuisa mariri uye zvichava aurayiwe. страницы? Asi chii chiri kurehwa zviri code, iyo akaurayiwa kamwe chete: kana rokukwidza (reloading) peji? Zvinoita yokuisa kutanga tsika vamwe variables vasingakoshi.

Script - nzvimbo ino ndiyo tsananguro rworudyi variables uye mashandiro pane wakanaka romutemo rakanyorwa kuti zvindinakire ini pachangu. Zviri seti mitambo kunokosha uye chinokosha, zvichida - yakawiriranwa zvakananga kubatana kwavo, asi kakawanda zviri zvakasiyana. Place tsanangudzo mashandiro uye nzvimbo chikumbiro yayo haisi chinhu chimwe.

Hazvina zvakafanira kuti mashandiro vachadanwa mumwe basa zvakananga, asi zvinogona kuitwa zvisina kunanga kubudikidza inotungamirwa guru remitemo. A mushanyi anotora sarudzo mukati bumbiro iri uye anoshanda zvakasiyana hurongwa mabasa.

dzichipfekeka emuchina

Functional emuchina - harisi chete uye kwete zvakawanda handlers dzavakatumirwa peji zvinhu ndiwo mabasa kuti zvinoumba pezvokuvamba peji, uye pakarepo handlers, zvakare, unogona kushandura.

The chiito anotora nzvimbo papeji, zvichienderana okunze uye muenzi maitiro pamusoro payo. Movement of negonzo, keyboard, mabhatani, the clicks, zviitiko, zvinhu uye mamwe mamiriro ezvinhu kutungamirira kushanda anodiwa mabasa.

Pakutanga hapana kusachinja-chinja uye hapana dzakafanana. Pane mukana wakakwana pakupindurwa web-upfumi zviitiko. How kutsanya JavaScript anozadzisa imwe basa napo dzakawanda zvekushandisa (kombiyuta, kukurukurirana mitsetse) uye kupindirana kwemuvanzrira wezvirevo nemabviro (pfungwa algorithm, pasi nzvimbo, kureva dambudziko) zvinhu.

Kutaura zvazviri unogona angapokana kuti chinhu akaita zvakafanana, asi chinhu vachadzokera pashure chinhu, asi zvinorehwa chinokosha ichi hachisi. Zvakakosha kuti JavaScript basa - ndiwo mukana uvhure zvakakwana Achipindura zviito mueni.

Izvi mafungiro matsva ari design: vakagovera kubudiswa makadzika rimwe Browser!

The nemarongerwo nokuti variables uye mabasa

JavaScript-variables anoiswa mukati chipepa «manyorero», uye mumuviri mashandiro. Mabasa anotsanangurwa saizvozvo. Special zvinoreva kunyora mukati mashandiro pane rimwe basa, asi zvingava zvakakodzera nezvikonzero zvakasiyana-siyana, uye zviri zvikuru musoro.

Description of basa kazhinji kunotanga guru «basa», zvichiteverwa zita raro, mazita kukakavadzana muzvikomberedzo, akaparadzaniswa nevanhu nezvitura befu, uye mashandiro muviri kufamba ndakaisa simbi mumakumbo.

In muenzaniso uyu, mabasa maviri vanotsanangurwa kuti zvinopa AJAX-mukutsinhana pakati peji uye Server. Neimwe scXHR pamusoro apa, nekuti rinowanika vose InitXML, uye mukati WaitReplySC.

Mashandiro zita uye parameter "basa"

Pane rave akapa asynchronous shanduro apo JavaScript-basa basa anonzi mushure Server apindure. Saka, zvatinogamuchira mhinduro kubva Server, WaitReplySC accesses papeji Tag, inozadza mashoko awanika uye kunokonzera vamwe mabasa, izvo zvingaita zvakanaka kutanga inotevera chikumbiro kuna Server.

Pano zvinokoshawo kuziva kuti WaitReplySC - munhu basa. scXHR.onreadystatechange = WaitReplySC она передается как параметр. Asi mumutsetse scXHR.onreadystatechange = WaitReplySC zviri akapfuura kuva parameter. Izvi Kazhinji kuchinjirwa mashandiro vamwe mabasa sezvo parameters. Rwakavakwa mumabhuraketi akavapa parameter ayo (s) - mashandiro achange vaurayiwe pakarepo. Haazvibatanidzi nezita chete, zvakanaka saka chii. Call basa achaita uyo weava zita.

The functionality chinozoiswa Via AJAX, kunoita kuti kuzodana JavaScript mashandiro kuburikidza nemashoko vakagamuchira kubva Server. Kutaura zvazviri, kutuma chikumbiro kuna Server, mumwe kana mumwe chikabviswa murege zvachose "ziva" izvo kushanda iye akatendeuka, uye chii ruzivo.

Out nerevane ayo mugumisiro

Muviri mashandiro, unogona kunyora chero mutauro dzaishandisa, uyo, Chokwadi, nokuti akaronga. Inside zvinhu vari variables akazivisa mukati nekunze, asi kwete avo zvinorondedzerwa muna mamwe mabasa.

Kana uchida mashandiro kudzoka Izvi, unogona kushandisa JavaScript kudzoka okuti: kudzoka. Muviri mashandiro angava zvinoverengeka yokudzoka mashoko zvakakwana. Hazvina zvakafanira kuti vose vachadzoka mugumisiro kwakadaro.

Kazhinji, Developers vari vairemekedza mukana uyu uye, zvichienderana nemamiriro ezvinhu, kusarudza kusada basa nokukurumidza.

Hazvina runodiwa rose algorithm mitambo, kana unogona kubuda adarika.

shanda zvinogutsa

Yaitaurwa Apfuura kuti mashandiro list, akaparadzaniswa nevanhu nezvitura befu, vari akanyudzwa muzvikomberedzo, uye inongova pashure zita rake. Mibvunzo inoshandiswa mazita shanduka, asi unogona kupfuura tsika zvakananga. Zvakaitika mumwe JavaScript basa iri basa, iwe chete vanofanira tsanangurai zita rayo pasina mumabhuraketi.

Inside mashandiro inowanika shanduka nenharo, ine urefu pfuma. Unogona kureva chero nharo mashandiro kuburikidza nenharo [0], nharo [1], ... kune vekupedzisira nharo [arguments.length-1].

Changing mashandiro renharo riri kunze here mukati mashandiro asi kwete. Kuti kushandura chinhu kunze mashandiro, iyo opareta anofanira kushandisa JavaScript dzoka, kuburikidza vanopfuura runodiwa ukoshi kunze.

Mushure mashandiro apedza, zvose dzaiva nechokuita ayo Implementation, richaparadzwa. Munguva kuurayiwa mashandiro anogona kuchinja zvokunze variables, asi avo zvinorondedzerwa muna mamwe mabasa, kusanganisira vaya vari menyika.

Tine zvikonzero callee pfuma, iyo zvichiitirwa kudana basa kuti rinoitwa pane imwe nguva. Kana chikonzero pacharo, iro JavaScript shanduro mashandiro ari kushanda kuti dzika recursion.

kushandisa mabasa

The kukoshesa the mashandiro - kushumira chiitiko Browser. Kuti aite izvi anenge ose chipepa anokwanisa tsanangurai chiitiko zita uye kushanda kwayo mukugadzira. Unogona tsanangurai zviitiko kakawanda, asi mumwe nomumwe chiitiko zvinoratidzwa chete basa rimwe.

Rimwe basa anogona kugadzirisa vakawanda peji zvinhu uye zviitiko shoma. Kuburikidza «ichi» Ipfungwa, unogona uchatamisa basa ruzivo apo rainzi.

Kushandiswa chaiwo pamusoro Nh-mashandiro - chiitiko handlers pamusoro okunze. In muenzaniso uyu scfWecomeGo () kushanda kana scfWelcomeCancel () akadanwa mazano / goho chimiro muenzi, uye kana kusarudza uchishandisa muoti scfMenuItemClick (ichi).

Mukupera zvazvingava, parameter akapfuura «ichi», izvo unokubvumira chishamiso kudzidza pane Diva yainzi. Chaizvoizvo, JavaScript zvichishandiswa qualitatively muchibereko muna Dom, uye saka nyore kunoita kuti kufamba zvinhu zvayo, kuunganidza mashoko anodiwa kuti mapeji rinomutsa anogona kungova nezvimwewo.

Mashandiro haana kudzokera tambo, nhamba, kana zvimwe ushande. Inogona kudzokera wenguva HTML-maatomu akafanana, uye inova zvaida nhamba okunze, pamwe handlers dzavo, zviitiko zvavo.

Nokuisa chinhu ichocho papeji, kuti yokuvaka pave functionality itsva kuti zvakanaka mashoko kugadzirisa dambudziko uye vanosangana zvinodiwa vashanyi, asi zvakaoma panyaya Implementation.

Sezvo Kugadzirwa yakadaro zvakazara, nyore kurasika mururimi code, mune basa zvinotoda, mune nguva akaumba kana kuti zviri mumwe kana mumwe peji. Asati kutora nhungamiro yakadaro okukura, vasadzikatidza tsime kuyera zvose.

On kuparadzira mafungiro

The yokuvaka ine kufunga pachiyero zvinhu zvose peji, zvachose zviitiko, uye vane mharidzo zvakajeka sei zvose chaizvoizvo zvinoitika. Zvakaoma, asi basa zviripo.

In JavaScript, mashandiro anogona kunonoka kusvikira vamwe chiitiko, uye izvozvo zvinhu zvingava zvakawanda, uye zviitiko vane tsika kupararira uye kupinda "zvoupenyu maonero" vakasiyana-siyana processors.

In muenzaniso uyu, kumwe pamberi basa rakanzi, iro rakatanga chinhu faira wekushandisa Muterere. Zvinofungirwa paging, riri hwindo nomwe chete mafaira, izvo zvinogona kubviswa uye kupatsanurwa. Inogona akatamira somunhu faira kuburikidza nekudzvanya pamusoro musara, uye museve kiyi namatombo nomwe mumitsara.

Muchiitiko chimwe nechimwe ine pachake nerevane. Nemamwe mashoko, ari muenzaniso nyore ichi, unofanira kunyora vaviri vakawanda zvinhu zvicharatidza sei zviitiko siyana, uye mimwe mitambo iyi achagadzirisa zvakasiyana siyana zvaungasarudza uye mamiriro ezvinhu kuti zviitiko havana nhengo.

Somuenzaniso, apo kubvisa pasi mutsetse inofanira misha upwardly. Izvi zvinoda kana kuita Kusarudzwa itsva kuti chenhando uye zvakajeka zvekuvaka, kana kuti kuverenga mitsetse, shandisa JavaScript basa riri mumitsetse uye kuti awane chinangwa waakashandisa.

The nharo uye Zvakabuda mashandiro

JavaScript unokubvumira kuunza bumbiro kuti "renguva dzaishandiswa" chinzvimbo. Kazhinji, kana nharo pakati mashandiro ndiyo mashandiro. Akabvumira Ipfungwa, mashandiro anodzoka ane basa. JavaScript vanoribvisa zvikuru zvakadzikama.

Ichi mashandiro akanaka, asi zvakaoma pachinhu Implementation. Zvazviri bvumidzwa semantically kugovera "dzichipfekeka" pfungwa yedzimudzangara chete anokwanisa yokuvaka.

Kana JavaScript basa iri basa - zvose zvakanaka, asi kana mashandiro zvinowanisa ane basa, uye kuti mumwe, pfungwa kwakaoma chaizvo kutevera. Kutaura zvazviri, mubvunzo haisi kana kushandisa unyanzvi, mubvunzo ndewokuti kuwana njodzi uye zvakarurama mugumisiro.

Developer nokutarisirwa zvakajeka uye zviri nyore. Pane dambudziko, unofanira kugadzirisa dambudziko, kwete kapukanana kufanana «JavaScript kukanganisa kuvhiyiwa kuri kusachengeteka» , zvibereko nechidzitiro, kana kurega zvose Browser injini.

Kana nharo iri basa, ipapo yokuvaka kupfuura munhu shanduka chaizvo ehupfumi, kuti haisi nhamba, kwete tambo, kwete chinhu. Asi kushandisa kwokukakavara kwakadaro kungaita kuti chokwadi kuti kuchinja kwokunze variables uye kunokonzerwa mashandiro kuuraya. Zvichienderana kuchinja achava yakakwana Kutamiswa.

Achipa vanowanika remitemo

Dzika kuuraya yekubvuma zvakapararira mukufamba basa mamwe code, zvinokwanisika pachishandiswa «eval». Hazvina kufungwa kuva chakanakisisa mhinduro, asi kazhinji havagoni omesa bumbiro remitemo pamwe zvisingakoshi mashandiro, uye kushomeka paumbwe sezvisingakoshi mudzinza JavaScript remitemo uye kungoita zvandakatonga nayo.

In muenzaniso uyu, zviri muwedzero aumbwa Musono kupinda operable div mamwe mashoko. Diva uye ruzivo kugutsikana kuti siyana nhamba akasiyana mwero nekuti zvakadaro chisarudzo mumamiriro ezvinhu haripi inosimbiswa mamiriro ezvinhu «JavaScript kukanganisa kuvhiyiwa kuri kusachengeteka» , asi zvakasimba kupa zvinozoita.

Nuance JavaScript paradigm kusuduruka "basa iri basa"

Kana kuita pasina frills, zviri nani kuti kurishandisa. All zvaungasarudza aya akanaka. Chokwadi, kakawanda kacho, ndiro chete kuzvipedza.

A muenzaniso chaiwo pamusoro recursion: yacho factorial. Zvakaoma zvakakwana kunyora algorithm kuti vachatitaka loop, asi zviri nyore chaizvo, unogona kusundira hamvuropu tsika. Factorial ari kukura zvakare kutsanya.

Zvisinei, recursion, uye mashandiro anodana mumwe basa, izvo zvinogona kuita uchiziva callback - kwomuzvarirwo zvinhu.

Somuenzaniso, imwe tafura dzose. Mumwe tafura kungava tafura. Nesting hazvigoni kudzorwa. Nyora rimwe tafura pachake yakatarwa ayo zvinhu - rakawandisa hwokusanyara.

Mienzaniso yakadaro izhinji, uye izvi zvose richava chaiye uye zvenzara dambudziko, kwete nekuda mapurogiramu. Ndokusaka dambudziko riri pakuti hapana-frills regai kumisa kwegadziriro mashandiro, kutaura zvazviri, ayo debugging kwaizotevera yakavimbika oparesheni anova JavaScript hanya, uye Developer.