PHP Practice: kirtani kwatanta

PHP ne mayar da hankali a kan mai kyau bayanai handling. A ginin kalma da harshen da aka wakilta cikakken aikin sa na kwatanta ayyuka, kirtani aiki, da kwatanta aiki.

Duk wani algorithm - a jerin na zabi da kuma ayyuka. Amma kafin ka yi zabi, kana bukatar wani abu to kwatanta shi da wani abu. Line - mafi capacious, m da m algorithm iko inji. Line - wani bambanci na data gabatar. A data - wannan shi ne babban batu na "kula" na wani algorithm.

Talakawa dabaru "kwatanta-mataki"

A general, tsauri bugawa harshe ya aikata wani bambance-bambance a cikin bayanan, kamar PHP kwatanta layi da kuma lambar ne ba yawa daban-daban. Number - shi ne ma wani layi, a lõkacin da ta ƙunshi kawai lambobi, batu da kuma a can ne ba guda harafin da cewa ba a yi amfani da su wakilci lambobi a cikin wani fom (ilmin lissafi tsarin rubutu).

Idan kontenkatsii lambar ta atomatik shigar da line, ba tambayoyi tambaye kuma babu wani boye kurakurai, ko idan gettype () aiki bada 'lamba' ko 'biyu'.

Duk da haka, akwai bambanci a tsakanin yin amfani da is_int () da kuma is_numeric (). A farko yana ba da gaskiya, kawai a lokacin da siga wani lamba, na biyu, a lokacin da wani yawan, ko Tazarar kirtani (m irin ne 'kirtani', amma qunshi duk bayar ilmin lissafi tsarin rubutu).

Wannan shi ne mai sauki misali - mai kyau misali na yadda wani PHP kirtani kwatanta aiki ( '==' '===' ... '! =') Za a iya gabatar da yawa surprises. A canji iya canza su irin, ba su da ko da yaushe lambobi, amma kusan ko da yaushe su iya kai ga line. A wani matsanancin hali - shi zai zama wani komai a kirtani.

Bisa ga sama, a PHP kirtani kwatanta aiki ne mafi m. Me daidai to zabi, don yanke shawara da developer. Kuri'a na zabin samuwa har zuwa yau da kullum maganganu.

Iyakoki na samuwa aikin

PHP-kwatanta da jeri biyu ne mai kyau "yi" aiki strpos () - mafi arha, da aminci, kuma m zaɓi. Idan da sakamakon da aiki da lambar, sa'an nan a fili daya kirtani ne daidai da wani ko wani sashi zuwa wani.

Matuƙa, m, amma kuma cikakken dama m - da amfani na yau da kullum maganganu.

Idan aiki $ cResult = scCheckFileName ($ cStr) ba 'gaskiya', sa'an nan da line ne da sunan fayil vordovsky. Ya za daya kawai zaɓi na fadada '.docx' kuma babu haruffa a cikin sunan: kawai haruffa, lambobi da kuma haruffa da '_', '-'.

The aiki za a iya sauƙi tuba zuwa wasu daban na fayiloli: $ cPtr = '/^([a-zA-Z...0-9\-\_]{4,239})\.(html|js|css|png|jpg | docx | txt) {1} $ / u '. Wannan bambanci kara zangon scan line sauke (msl, PHP kirtani kwatanta aka yi amfani da "upload fayiloli zuwa uwar garken, ba tare da wani zarafi na shigar da kuskure") ga html, JS, CSS, ...

Amfani da strpos () da kuma preg_match () - matuƙa. Suna ba kai tsaye alaka da batun na kwatanta lokacin. Amma tambaya na algorithm - shi ne wani al'amari na amfani da haɗin style, da yin amfani da dukkan damar da za ka kai wani abin dogara da kuma daidai sakamakon.

Aikin PHP: kirtani kwatanta

Arsenal harshe idan aka kwatanta da kirtani - mai tsarki, ba kawai da kwatanta aiki, amma kuma a hade da wani search ko canza kai tsaye. Ba ko da yaushe aiki dole ne yayi daidai da kwatanta, tun karshen ba dole ba ne kai ga wani canji a wani jere. Sau da yawa kana da zabi daya ko sauran reshe na algorithm.

Al'ada bambance-bambancen PHP: aikin kirtani kwatanta aiki int strcmp (s1, s2).

A sakamakon da aikin:

• 0 - line ne daidai.
• -1 - na farko kirtani ne kasa da na biyu;
• 1 - na farko da fiye da biyu jere.

A aikace, wannan yana nufin cewa na farko jere zuwa na biyu, daga abin da PHP aiki (kwatanta layuka) yanke shawarar. A mafi iyaka version of strpos (), saboda a karshen harka shi ne mai yiwuwa a san matsayin da shigarwa.

strcmp () aiki - m. Idan kana so ka kwatanta da kirtani-m, PHP offers da strcasecmp (). A ginin kalma ne irin wannan.

A yi sau da yawa ake bukata da aiki ba tare da dukan line, amma kawai na shi. Domin wannan sa na ayyuka PHP (kirtani kwatanta) hada strncmp (s1, s2, N). The uku siga ƙayyade yi da kwatanta kawai N-bytes. A sakamakon haka ne irin wannan strcmp ().

Iri-iri, kirtani da kuma gwada

Wadannan ana kusan ko da yaushe wakilta kirtani. Idan muka yi la'akari da iri-iri, abubuwa, ko data Tsarin, yana da kawai daban-daban bambance-bambancen karatu na haduwa da wani sauki kirtani Tsarin.

Kirtani iri-iri da kuma layuka za a iya bayar a wani karin hanya. Canji na tsararru a cikin wani layi aiki implode (tsararru, alama ce), misali: $ margins1 = implode ( ',', $ style-> getInnerMargin ()). ... da algorithm / mai amfani .... $ Margins2 = implode ( ',', $ style-> getInnerMargin ()) ba ka damar ci duk abu matsayi a cikin kirtani matsayi.

Za ka iya sa'an nan tsayar da PHP kirtani kwatanta, kuma a lokaci: $ rajistan shiga = strcmp ($ margins1, $ margins2) da kuma tabbatar da algorithm ko da mai amfani da wani abu ya canza (ko a'a). Idan ka yi a kwatanta a cikin saba hanya, za ku ji da a gaggauta warware tsararru abubuwa. Yana daukan tsawon kuma shi ne mafi rikitarwa.

Abubuwan da layi

Ko da more m amfani PHP (kirtani kwatancen) za a iya aiwatar via abu-daidaitacce ideas.

A zamani ra'ayin da wuraren nuna cewa suna da dũkiyarsu da kuma hanyoyin. Tsohon yawanci wakilta lambobi, kirtani, iri-iri, da kuma sauran abubuwa. A karshen sau da yawa sun hada da rikodi dabaru (sa) a cikin dawo da layin kuma daga line (samun).

Ba kamar iri-iri, da abu ya aikata aikin da nasu dũkiyarsu da kuma interacts tare da sauran abubuwa. Object "m" a cikin abin da kaddarorin ne na real darajar da algorithm na shirin matsayin dukan.

Wannan lokacin bayar da wata-akai da kuma damar zuwa rikodin lokacin da rikodin wani layi kawai dole bayanai, da kuma a cikin dawo da layin ya mayar da dukan aiki Properties a da ake so jihar. Yawancin lokaci, a kowane abu akwai gwaji bayanai da kuma aiki (lokaci). Da aiwatar da wannan ra'ayin ba ka damar ceton ba kawai memory, faifai sarari, da database rikodin, amma kuma ya sa ya yiwu kwatanta Lines sauki kuma mafi m wajen.

Ginin kalma da kuma ilimin harsuna

PHP ne masu tasowa, da kuzari, da kuma ta aiki biyu cikin sharuddan gwada kirtani da kullum da inganta cikin sharuddan su magani. Duk da haka, kome ya hana a developer don matsawa da cibiyar nauyi a yankin na ilimin harsuna.

Lalle ne shĩ, aiki ne mai kyau, amma da amfani za a iya canjawa wuri a cikin ma'anar code a abubuwa. Lokacin da algorithm da aka gabatar a matsayin tsarin na hulda tsakanin abubuwa, shi ya dubi sosai fiye da jerin misãlai, kuma ayyuka a cikin kai tsaye jerin, wani gargajiya style.