JS foreach shay sida muuqashadii

JavaScript Saan bixisaa awood u leeyahay inuu isu geeyo doorsoomayaasha galay Arrays iyo walxaha. Helitaanka waxyaabaha laga heli karaa via jirrabo iyo magacyada dhex shaqeeya wareeg.

Laakiin waxaa suurto gal ma aha had iyo jeer in la ogaado tirada cunsur ee ururinta waqti design oo aan had iyo jeer waa habboon in la isticmaalo Saan la siiyo kelmedo ku dhex.

design classic

war loop Normal "for (var i = 0; i

var i = 0;
halka {... aData [i] (typeof aData [i] = 'undefined'!); ... i ++; }

marka tirada xubno aan la garanayn.

Waxa kale oo aad ku dhisi kartaa algorithms kala duwan ee buuxintii iyo processing soo diyaariyeen, laakiin si ka badan habboon in la isticmaalo ee, kala duwanaansho cusub oo casri ah waa.

Classic wanaagsan marka aad u baahan tahay si loo farsameeyo HR weydiimaha (magaca qoyska, magaca hore, meel), kaararka qalabka (model, soo saaraha, iibiyaha, taariikhda sale), iyo macluumaadka kale ee la qaab ahaan ma beddeli iyo matalaan danta wadareed.

Marka element isugu soo laftiisa in uu yahay shay ama qaab-dhismeedka in wuxuu leeyahay sifooyin u gaar ah iyo hababka ay, ma la qabsan karaa dhaqdhaqaaqa classic tirada iyo tayada, iyo qaadataa macnaha soo diyaariyeen a kala duwan.

loop Foreach

dhaqdhaqaaqa waa sifooyinka muhiimka ah muujinta dhabta ah element soo diyaariyeen. Design JS isugu soo foreach, in xoogaa ka duwan sida caadiga ah ee (ansixiyay in luqado kale), version, noo ogolaaneysa in ay bixiyaan diyaariyeen ah ee fursad si ay u muujiyaan guryaha ay dhex taariikhda uu element.

Ka soo qaad mid soo diyaariyeen kooban waddo (sifooyinka ay tayo iyo tiroba), oo isugu soo kale - gawaarida in safri karaan oo kaliya on waddooyinka qaarkood oo ay leeyihiin haamaha shidaalka mugga kala duwan, i.e. masaafada u dhexeysa maaddooyinka sidoo kale waa muhiim.

In muuqashadii sida an isku geynta ku haboon waa in ay qaadaan saldhig, tusaale ahaan, waddooyinka iyo dooran baabuurta in ay awoodaan in ay la wado waxa ay noqon doontaa. Oo waa ka sii wanaagsan, haddii ay waddada iyo gaariga oo la hadlayay barnaamijka sida walax, "isku arkaan." Tani waa codsi dabiiciga ah ee barnaamijyada wax-u janjeedha, taas oo, iyo waxyaabo kale, ma u baahan tahay in la beddelo geynta ee la beddelo wadada iyo baabuur ururinta, si toos ah magdhow ah dayactirka wadooyinka, dayactirka baabuurka iyo wixii la mid ah

Farsamo ee qaab-dhismeedka foreach JS waa mid aad u fudud: "aData.forEach (fData);", halkaas oo fData - shaqo ah in waxaa laga codsadaa in element kasta oo soo diyaariyeen aData ah:

shaqayn fData (qiimaha, index) {sText + = index + '=' + qiimaha + '; '; }.

Haddii xogta isha ka wakiil yahay sida soo socota:

var aData = [1,2,3,4];
aData.push (11);
aData.push (22);
aData.push (44);
aData.push ( 'line 1');
aData.push ( 'line 2');

var sText = '',

natiijada isticmaalka sida JS foreach doono:

"0 = 1 1 = 2 2 = 3 3 = 4 4 = 11, 5 = 22, 6 = 44, 7 = line 1, 8 = line 2,".

Features walxaha Array

Wax on JavaScript - gaar ah. Isticmaalka waxyaabaha ku saabsan luqadda this waa weyn u kala duwan ka fulintii afaf kale. Shay - fikirkani waa soo diyaariyeen ah ee guryaha iyo hababka. Iyadoo dambaysta ah dhab u samayn ficilka, badbaadinta ama sixiddiisa ay ka kooban tahay ama wax kale oo shay dibadda, Arrays, doorsoomayaasha.

waxyaabaha soo socda galay isu diyaariyeen sidii loox on filinka ka, marka iterating ee JS dhismeedka wax foreach u sameeyaan a kelmedo cusub: qorshee dareen variable.

Sidaas daraaddeed, wadada ahaantooda ay awoodaan in ay doorta gaari ku raaci karaan iyaga oo ku saabsan, iyo maalinta la soo dhaafay waxaa lagu sifeeyay wadooyinka la heli karo. Haddii aadan fiiro, in shaqo ee xulashada barnaamijyada this code lagu kalsoonaan karo oo dheeraad ah, hawsha - si loo ogaado wadada bixinta - dhigaysa JS foreach dhisaan in xal macno leh oo fudud: balaadhinta waddooyinka waddooyinka, dooro mishiinka iyo fuliyaan bixinta badeecadaha.

Haddii waddooyinka, jidadka iyo mashiinada - arrays oo alaab ah, isku geynta ah waxa si wayn u fududeeyay. U muuqato la yaab leh in soo bixitaanka of dhismeedka foreach JS inta raagay. Si kastaba ha ahaatee, inkastoo uu daacad u ahaa hal dhibic ka, ku dhaqanka waa ay adag tahay in ay fuliso.

Layliska foreach oo dhab ah walxaha JS

Fikirka sameeysa casriga ah ula shaqeeynayo walxaha caanka ah barnaamijyada, laakiin ma aha waxyaalaha dhibaatada dhabta. Aan caadi fahamsan yahay by kuwa baabuurta wadada, wadada, masaafada u ...

barnaamijyada wax-u janjeedha ayaa waxaad fartaan Wannaagga Waddooyinkiisa qodxan, iyo dhaqan ahaan loo qaaday si ay u abuuraan dagaal isugu diyaariyeen wax barnaamij ah, foomamka, badhamada, wadada sanduuqa doorashada, iwm

Intaa waxaa dheer, foreach JS oo ay la socdaan dhista kale luqadda waxaa lagu qabtaa browser booqdaha ee keenta in tababar la dhaafi karin oo halis ah. Ma sameeysa walba diyaar u yahay inuu la wadaagto ay code. tusaalooyin wax ku ool ah isticmaalka Arrays iyo ururinta shayada dhab ah - hab wanaagsan oo in la hagaajiyo aqoonta.

Si kastaba ha ahaatee, helitaanka code JavaScript si loogu isticmaalo sameeysa waye saameyn dadban ku saabsan horumarinta fikradaha rajo for a walxaha firfircoon oo dhabta ah ee dunida. dhismaha foreach JS aan weli waa qumman yahay, iyo horumarinta kelmedo ay u muuqataa in ay jihada aad u rajo.