Javascript, magana na yau da misalai, duba magana na yau da

Kafin zuwan hypertext harshe, amma a maimakon haka, sai ya bayyana cewa ya kamata mu ba kawai duba, amma yin haka a karkashin wani yanayi, musamman, a wata wuri, a karkashin sauya data a dama yawa, da saba search da kuma maye gurbin aiki shirya wani nagartaccen shirye-shiryen. Ƙirƙiri Masterpieces na art search a shirye-shirye da harsuna, da kuma database fice a cikin siffofin Samfur yanayi, sanye take da adana hanyoyin, triggers da sauran hanyar ƙato samfurin da zumunci bayanai waƙoƙi. Bayyanar da magana na yau da ga juyin juya halin da bai kai ba, amma shi ya kasance mai amfani da kuma m hanyar samun da kuma maye gurbin bayanai. Alal misali, yau da kullum maganganu JavaScript imel muhimmanci rage wuya rajista na baƙi, kada load da yanar aika saƙonni zuwa ƙarancin adiresoshin.

Don ce cewa a JavaScript magana na yau da yake mafi alhẽri produmannnyh jerin indexOf () kira a cikin firam na al'ada cyclic da aiki, ba zai iya amma cewa shi ya sanya rubutun code shi ne m, amma kadan comprehensible ga uninitiated, na iya zama ainihin.

Object RegExp = + samfuri engine

Regular maganganu - shi ne mai template + engine. Na farko shi ne ainihin wani magana na yau da - JavaScript abu - da RegExp, na biyu - da wannan samfuri mai yi, yi amfani da shi zuwa ga line. Engines da aiwatar yau da kullum maganganu ga kowane shirye-shirye da harshen ne daban-daban. Kuma ko da yake ba duk da bambance-bambance ne muhimmi, shi ya kamata a haifa tuna, kazalika da tabbatar da su a hankali duba da magana na yau da kafin ta aiki.

A musamman tsarin rubutu lokacin rubuta yau da kullum maganganu mai sauki ne yin amfani da da kuma quite tasiri, amma shi na bukatar kula, neatness da kuma hakuri daga developer. By tsarin rubutu magana na yau da alamu bukatar don amfani da su. Wannan ba wani fad, shi ne da dabaru na wani inji aiwatar «JavaScript yau da kullum maganganu."

Salon magana na yau

Yarda biyu zaɓuɓɓuka:

var expOne = / ABC * / i;

var expTwo = RegExp ( "ABC *", "i");

Yawanci shi amfani na farko Hanyar. A karo na biyu idan, da quotes, domin su yi amfani da harafin '\', dole ne a tsere da janar dokoki.

'I' - flag nuna "harka m". Zaka kuma iya amfani da flags 'g' - «Global Search 'da kuma' m '- Multi-line search.

A alama ce '/' domin nuna kowa yin amfani da samfuri.

A farkon da kuma karshen magana na yau da

A '^' ma'anar da harafin (s) daga wanda ya fara da magana na yau da, da kuma '$' kayyade wadda harafin (s) dole ne ya zama a karshen. Ya kamata ka ba gwaji tare da su cikin wani magana, inda suka yi daban-daban ma'anar.

Alal misali,

var eRegExp = sabon RegExp (cRegExp, 'i').

var cRegRes = '';

var sTest = 'AbcZ'.

idan (eRegExp.test (sTest)) {

cRegRes + = '- Eh'.

} Else {

cRegRes + = '- Babu'.

}

var dTestLine = document.getElementById ( 'scTestLine').

dTestLine.innerHTML = 'Zancen /' + cRegExp + '/ for jere "' + sTest + '"' + cRegRes.

A kashi 'scTestLine' zai haifar (cRegExp m yana da wani m ma'anar):

magana / ^ AbcZ $ / domin kirtani "abcz" - a

Idan ka cire 'i' flag, sakamakon shi ne:

magana / ^ AbcZ $ / domin kirtani "abcz" - Babu

Abinda ke ciki na wani magana na yau da

A magana na yau da ita a jerin haruffa, wanda shi ne batun da search. Zancen / qwerty / neman shigarwa ne wannan jerin:

magana / qwerty / for kirtani "qwerty" - a

magana / qwerty / for kirtani "123qwerty456" - a

A '^' canje-canje ne maganganu:

magana / ^ qwerty / for kirtani "123qwerty456" - Babu

magana / ^ qwerty / for kirtani "qwerty456" - a

Hakazalika, domin karshen layi alama. Regular maganganu da damar ga daidaito: misali, [az], [AZ], [0-9] - duk haruffa daga cikin haruffa a cikin wannan harka ko Figures. Rasha haruffa kuma za a iya amfani, amma ya kamata kula da tsarinsa na kirtani (wanda ake nẽman cewa an nemi) da kuma shafukan. Sau da yawa Rasha haruffa, kazalika da musamman haruffa, shi ne fin so zuwa kafa dokokinsu.

Lokacin da kafa magana na yau da iya saka zažužžukan for gaban wasu alamu cikin wani musamman wuri, tare da adadin su ba kamar haka: '*' = 0 maimaitawa ko fiye sau. '+' = 1 ko fiye maimaitawa sau. {1} ne guda, kamar yadda '+'. {N} = maimaitawa daidai n sau. {N,} = n maimaitawa sau ko fiye. {N, m} = maimaitawa n ga m sau.

Amfani da baka, ba za ka iya saka harafin da kafa na zabin. Yana kama da wannan. [ABCD] = [ad] = kowane hudu alama ce: 'a', 'b', 'c' ko 'd'. Za ka iya saka in ba haka ba. Duk wani hali wanin wadanda kayyade a cikin sa: [^ ABCD] = wani hali wanin 'a', 'b', 'c' ko 'd'. '?' Yana nuna cewa a wannan lokaci da alama ba zai iya zama. '.' ƙayyade wani hali wanin nuna newline. Wannan '\ n ",' \ r ',' \ u2028 'ko' \ u2029 '. The magana '\ s * | \ S *' = '[\ s | \ S] *' na nufin search for wani hali, ciki har da newlines.

Saukake versions na magana na yau da

The magana '[\ s | \ S] *' - search sarari, ko rashin itãcensa, cewa shi ne duk da cewa an a kan layi. A wannan yanayin, da alama '\ s' ya nuna a sarari, da kuma '\ S' - da yake babu.

Hakazalika, za ka iya amfani da '\ d' don bincika gidan goma lambobi, da kuma '\ D' sami wani maras Tazarar hali. Tsarin rubutu '\ f', 'r' da kuma '\ n "dace da tsari-feed, karusa dawo da kuma line-feed.

A tab hali - '\ t', a tsaye - '\ v'. A nadi '\ w' iske wani Latin haruffa harafin (haruffa, lambobi, da kuma, a san mark) = [A-Za-z0-9_].

A nadi '\ W' shi ne daidai da [^ A-Za-z0-9_]. Wannan yana nufin wani hali da ba wata wasika daga cikin haruffa, yawan, ko '_'.

Search harafin '\ 0' = search NUL haruffa. Search '\ xHH' ko '\ uHHHH' = Search hali code ko HHHH HH bi da bi. H - hexadecimal lambobi.

Shawarar wording da kuma coding na magana na yau da

Duk wani magana na yau da muhimmanci a hankali gwada a kan daban-daban versions layuka.

Tare da gwaninta na samar da wani magana na yau da kuskure zai zama karami, amma duk da haka ya kamata ko da yaushe a kiyaye tuna cewa nasu ilimi daga cikin dokoki na rubutu na yau da kullum maganganu ba zai iya zama gaskiya, musamman a lokacin da "yau da kullum kakar" da aka canjawa wuri daga wannan harshe zuwa wani.

Akwai hanyoyi tsakanin classic (daidai nuni) da kuma wani Saukake version of mai magana na yau da, shi ne mafi alhẽri fi son na farko. Bayan duk, a cikin litattafansu da aka yaushe a fili ya nuna cewa duka ya nema. Idan magana na yau da ko search kirtani da Rasha haruffa, ya kamata kai ga guda shigar da duk Lines da page on wanda aiki sami JavaScript-code aikin wani magana na yau da.

Lokacin da akwai wani hali da aiki, ba-Latin haruffa, shi ya sa hankalta to la'akari da wani nuni da halin da lambobin, ba haruffa kansu.

Lokacin da za'a aiwatar da search lissafi mai tsauri a JavaScript magana na yau da ya kamata a hankali bari. Shi ne da muhimmanci musamman don sarrafa hali tsarinsa.

A parentheses a cikin magana na yau da

The baka ayyana zažužžukan ga alama, wanda dole ne ko ba zai zama a wani wuri, da kuma zagaye - jerin bambance-bambancen karatu. Amma wannan shi ne kawai wani janar mulki. Daga shi babu wani togiya, amma akwai wani m iri-iri na aikace-aikace.

var cRegExp = "[az] * (PNG | jpg | gif).".

var eRegExp = sabon RegExp (cRegExp, 'i').

var cRegRes = '';

var sTest = 'picture.jpg'.

idan (eRegExp.test (sTest)) {

cRegRes + = '- Eh'.

} Else {

cRegRes + = '- Babu'.

}

sakamakon:

/[az]*.(png|jpg|gif)/ magana ga line "picture.jpg" - a

/^[ad][az]*.(png|jpg|gif)/ magana for "picture.jpg" line - Babu

/^[ad][az]*.(png|jpg|gif)/ magana ga line "apicture.jpg" - a

/^[ad][az]*.(png|jpg|gif)/ magana for "apicture.jg" line - Babu

Ya kamata a lura cewa duk, sa'an nan wani alama zai iya zama ba sifili sau. Wannan yana nufin cewa "yau da kullum kakar" iya aiki a m hanyoyi a kalla.

Duba RegExp - gwajin imel

A yau da kullum da JavaScript magana samu hanyoyi guda biyu, gwajin da kuma exec, kuma za a iya amfani da a Lines abubuwa (Kirtani) a cikin hanyoyin (ayyuka): search, tsaga, maye gurbin da wasan.

gwajin Hanyar an riga an nuna, shi ba ka damar duba correctness na magana na yau da. Hanyar Result: gaskiya / ƙarya.

La'akari da wadannan JavaScript yau da kullum maganganu. Duba imel daga yawan "wuya, amma lalle":

var eRegExp = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s @ "] +) *) | (". + ")) @ ((\ [[0-9] {1,3} \ [0-9] {1,3} \ [0-9] {.. . 1,3} \ [0-9] {1,3}]) | (([a-Za-Z \ -0-9] + \.) + [a-Za-Z] {2}) ) $ /;

kirtani var sTest ='SlavaChip@sci.by 'ba gaskiya, to, akwai wannan kirtani ne daidai imel-imel. A duba da aka gudanar eRegExp.test (sTest).

Practical amfani: jiyya na e-Mail

Exec Hanyar samar da fitarwa tsararru, kira:

var aResult = eRegExp.exec (sTest).

cRegRes = '
' + aResult.length + '
'.
domin (var i = 0; i cRegRes + = aResult [i] + '
'.
}

Yana bada wadannan sakamakon:

9
Slava.Chip@sci.by
Slava.Chip
Slava.Chip
.Chip
maras bayyani
sci.by
maras bayyani
sci.by
sci.

Sauran hanyoyin da aiki kamar wancan. An shawarar duba su fitar da kanka. Ci gaba da kuma yin amfani na yau da kullum maganganu, shi ne kyawawa aiki a yi, da code kwashe ba ko da yaushe bu mai kyau a nan.

Popular "yau da kullum kakar"

JavaScript magana na yau da bai wa Email ba kawai akwai wasu karin sauki zabin. Alal misali, /^[\w-\.]+@[\w-]+\.[az]{2,3}$/i. Duk da haka, wannan embodiment daukan la'akari ba duk embodiments na adireshin imel da rikodin.

Hakika, dole ne ka duba kwarewa da abokan aiki, don nazarin yadda za su samarwa kafin a tsara nasu a kan JavaScript yau da kullum maganganu. Amma akwai wasu matsaloli. Kada mu manta cewa wani JavaScript yau da kullum maganganu (misalai na lokacin da ake kwashe) zai iya kofe da muhimmanci haruffa: '\', '/' ko quotes. Wannan zai kai ga kuskure, wanda ka iya bincika tsawon lokaci.

Yana da muhimmanci a yi la'akari da saba "adam girma." Bayan m JavaScript magana na yau da ga wayar, wanda zai iya zama baƙo (mutum), shi ne ba a hanyoyi daban-daban: 123-45-67, (29) 1234567, 80291234567 ko 375291234567. Kuma shi ke da wannan dama. Haruffan mahara alamu ne ba ko da yaushe m, kuma m kam na dokoki domin rubuta lambobi iya haifar da rashin jin daɗi ba dole ba, ko kuma hane-hane. Option / ^ \ d [\ d \ (\) \ -] {4,14} \ d $ / i ne dace da mafi yawan lokuta ka duba lambar wayarka.

Idan kana so ka yi JavaScript yau da kullum maganganu, kawai lambobi cak, har irin wannan sauki hali na bukatar bayani. Ya kamata a yi la'akari da wani lamba ko fractional, kimiyya tsarin rubutu, ko al'ada, tabbatacce ko korau lambar. Zaka kuma iya la'akari da kasancewar kudin alama ce, yawan lambobi bayan da gidan goma nufi da rabo daga cikin dukan ɓangare na lamba a kan triad.

Zancen / ^ \ d + $ / i duba kawai lambobin da /^\d+\.\d+$/i magana da damar yin amfani da wata aya don nuna fractional ɓangare na lambar.

A JavaScript dubawa na yau da kullum maganganu za a iya amfani da su nuna format na tukuru shigar da bayanai, wanda yana da muhimmanci, musamman a lokacin da shigar da bayanan martaba, fasfo bayanai, da kuma shari'a adiresoshin t. D.

Duba kwanakin - sauki ga hadaddun

La'akari da wani JavaScript yau da kullum maganganu. Misalai zuwa ranar, kamar yadda na yawan lambobin wayoyin tarho wakiltar zabi tsakanin rigidity da kuma sassauci. Kwanan wata na taron - daya daga cikin muhimman bayanai, wanda sau da yawa da za a gudanar. Amma kayyade da shigar a cikin wani takamaiman format: "DD-mm-yyyy 'ko' d.m.gg 'sau da yawa take kaiwa zuwa abokin ciniki rashin biyan bukata. A mi} a mulki daga shigar filin na rana-da-watan, cike da classic HTML-nau'i, ba zai iya daukar wuri a lokacin da ka shigar daya kawai lambobi, da kuma na biyu da shigar da iya zama da wahala. Alal misali, a cikin filin na ranar da aka gabatar da 3 da kuma na gaba da lambar 2 ba maye gurbin na farko, da kuma aka dangana ta 32, wanda, ba shakka, za su haifar da rashin jin daɗi.

Dace da kuma saukaka na yau da kullum maganganu da gaske dogara ne a kan general yi na tattaunawa tare da baƙo. A daya harka, don nuna kwanan wata da shi bu mai kyau don amfani daya da shigar da filin da siffan, a cikin wasu harka shi ne zama dole don samar da fannoni daban daban na rana, wata da shekara. Amma sai wani ƙarin "halin kaka na code" duba tsalle shekara, yawan watanni, yawan kwanaki a gare su.

Bincika da kuma maye gurbin, magana na yau da memory

JavaScript maye gurbin (na yau da kullum maganganu) ta amfani da hanyar na Kirtani abu, da kuma ba da damar mu sami darajar da canza shi nan da nan. Wannan na da amfani domin gyara bugawa kurakurai, gyara abinda ke ciki na da tsari filayen da kuma ga tana mayar data daga daya gabatar format zuwa wani.

var cRegExp = / ([a-z] +) \ s ([a-z] +) \ s ([a-z] +) / i; // lokacin da neman suna uku 'canji'

var sTest = 'wannan labarin ne mai kyau!'.
var cRegRes = sTest.replace (cRegExp, "$ 2, $ 3, $ 1").

var dTestLine = document.getElementById ( 'scTestLine').

dTestLine.innerHTML = 'magana' + cRegExp + 'domin kirtani "' + sTest + '" kunna:' + cRegRes.

sakamakon:

magana / ([az] +) \ s ([az] +) \ s ([az] +) / i ga line "wannan labarin ne mai kyau!" daga: da labarin ne mai kyau, wannan!

Lokacin yin kowane biyu na parentheses Stores sakamakon a cikin 'm' $ n, inda n - yawan sashi nau'i-nau'i ($ 1, $ 2, ...). Ba kamar al'ada, a nan m Ƙidayar ne 1, ba 0.

Janar shawarwari

Magana na yau da simplifies da code, amma lokacin da za a ci gaba da shi sau da yawa wani banbanci. Za ka iya fara da sauki kayayyaki da kuma sa'an nan Ya sanya mu hada a cikin mafi hadaddun maganganu. Za ka iya amfani da daban-daban online sabis don gwada yau da kullum maganganu ko musamman na gida da kayayyakin aiki.

A mafi kyau zaɓi za su haifar da nasu library na yau da kullum maganganu da nasu kayayyakin aiki, don gwada sabon aukuwa. Wannan shi ne hanya mafi kyau don ƙarfafa da kwarewa da kuma koyi yadda za a sauri gina abin dogara da kuma dadi zane.

Amfani da maimaitawa na haruffa da kuma kirtani, da cewa shi ne, musamman haruffa '*', '+' da Katakon, na nuna yawan maimaitawar kamata a shiryar da ka'idojin sauki da kuma expediency. Yana da muhimmanci a gane cewa mai magana na yau da zuwa farkon ta aiki, da kuma samun sakamakon ne gaba ɗaya a cikin ikon da engine amfani da browser. Ba dukkan harsuna ne daidai da JavaScript. Kowane browser iya kawo su na sirri, abubuwan daka zaba a cikin fassarar yau da kullum maganganu.

Karfinsu ba kawai shafukan da style zanen gado, na yau da kullum maganganu, shi ma yana yi. A page yana amfani da JavaScript, za a iya daukan wani da-aiki ne kawai a lokacin da shi ya samu nasarar yi aiki a kan da dama bincike.

JavaScript, Kirtani da RegExp

By da dama aiki a abokin ciniki matakin, cewa shi ne, a cikin baƙo ta browser a JavaScript, shi bukatar high basira da developer. Dogon isa kana da damar da za su cire kuskure JavaScript-code browser ta mallaka kudi ko da taimako na ɓangare na uku kari, code Editocin, m shirye-shirye.

Duk da haka, ba dukkan lokuta, da debugger iya rike da samar da kyau goyon baya ga developer, wani m kuskure ganewa, gane bottlenecks. The sau lokacin da kwamfuta da aka mayar da hankali a kan lissafin, a cikin m baya. Yanzu, da kulawa ta musamman ga bayanai da kuma line abubuwa sun zo taka muhimmiyar rawa. Yawan karfe kirtani, da gaskiya yanayi da suke hayyanãwa kawai a daidai lokacin da hakkin wuri.

Regular maganganu ƙarfafa yiwuwar Lines, amma bukatar kai da girmamawa. Cire kuskure RegExp a cikin aikinsa, ko da shi ne zai yiwu canzawa, ba ma ban sha'awa ra'ayin.

Fahimtar tsarin da kuma dabaru na RegExp abu, ma'ana abu Kirtani, da ginin kalma da kuma ilimin harsuna da JavaScript - a gaskiya amintacciyã, natsattsiyã code, barga aiki na kowane shafi da kuma site matsayin dukan.