Arrays - ib tug ... Ib tug nyuag taw qhia rau cov ntsiab lus

Leej twg uas tau kawm programming ntawm lub tsev kawm ntawv paub hais tias cov xib fwb yuav muab tsuas yog qhov yooj yim, yooj yim cov ntaub ntawv uas rau lawv cov tub ntxhais kawm. Subject arrays kuj raug xam tias yog, tab sis nyob rau hauv lub tom qab kev kawm. Yog vim li cas? Vim hais tias arrays - yog lub hauv paus uas tso cai rau lub programmer mus ua hauj lwm nrog cov loj tagnrho ntawm cov ntaub ntawv.

kev taw qhia

Hnub no lub ntsiab lus, peb yuav pib nrog lub fact tias peb paub lub ntsiab txhais ntawm tias lub sij hawm. Arrays - lub ntsiab lub cajmeem ib puag ncig, uas sawv cev rau ib tug set ntawm cov ntaub ntawv nyob rau hauv tabular daim ntawv los yog kab. Xav txog tej yam ib tug series ntawm random 1, 6, 2, 4, thiab 8. Nws yuav array. Txhua tooj sau nyob rau hauv ib tug kab, nws muaj nws tus kheej serial tooj, thiab hais tias yog dab tsi ua rau nws ua tau rau txog (coj) lawv nrog ib tug array ntawm programming.

cov ntaub ntawv

Xav txog yuav ua li cas lub arrays yog kaw nyob rau hauv xyaum. Cov ntaub ntawv, cim arrays - nws yog tsim los qhia lawv kev pab cuam hom (uas qhov tseem ceeb yuav tsum muab cia rau hauv lub array) thiab tus naj npawb ntawm hlwb. Tej zaum cov tsim nco array tsis specifying yog pes tsawg tsawg ntawm cov ntsiab, tab sis, ces koj nkag mus rau nws koj yuav tsum tau ceev faj heev uas qhov kev pab cuam yog tsis fixated thiab pib xa mus rau npliag hlwb.

• D: array [1..k] tiag tiag; - yog li sau lub array rau "Pascal". Yog hais tias koj yuav tsum tsim cov kev pab cuam paub tias koj yuav muaj ib tug tshaj plaws ntawm 5 ntsiab, koj muaj peev xwm siv lub nkag teb chaws D: array [1..5] tiag tiag;

Raws li tej zaum koj yuav tau twv D - yog tsab ntawv, lub ntsiab lus lub npe ntawm tus array; tiag tiag - qhov no yog lub hom (hom) ntawm cov ntaub ntawv uas tej zaum yuav muaj nyob rau hauv lub array; array [] - yog tus naj npawb ntawm array ntsiab.

tsis txaus siab

Nyob rau hauv thiaj li yuav ua hauj lwm nrog lub caij ntawm lub array, nws yog tsim nyog los siv cov kev pab cuam. Arrays - cov no yog cov tib tus neeg lossis cov lus, zoo li ib yam. Nyob rau hauv thiaj li yuav ua hauj lwm nrog cov array caij, nws yog tsim nyog los ua kom paub: D [1]. Qhov no yuav xaiv tus thawj lub caij ntawm lub array thiab rau kev ua hauj lwm nrog nws. Piv txwv li:

• sau (D [1]); - Qhov no hais kom ua yuav pab kom tus neeg siv yuav tso saib tus nqi uas muaj nyob hauv tus thawj cell ntawm lub array.

Nws yog ib nqi sau cia hais tias yog hais tias koj yuav mus nqa tawm zauv hauj lwm nrog arrays, ces koj yuav tsum xyuam xim rau cov hom. Koj yuav tau ua qhov no tsuas yog tias koj muaj ib qho array ntawm cov zauv. Kom nws dlaim phaj:

• Yog hais tias koj muaj ib qho array ntawm D: array [1..k] hauv cov ntawv nyeem; - thiab nyob rau hauv lub cell D [1] = 1, ces koj siv tsis tau no nyob rau hauv lej haujlwm vim hais tias cov kev pab cuam rau cov "1" - qhov no yog tsuas lo lus "ib", tsis tus xov tooj. Yog li ntawd saib ntau yam thiab lawv hom.

Yog hais tias koj npaj yuav xyuam xim ua hauj lwm, los yog nyob rau hauv ib tug array cia li yuav tsum tau muab cia rau tus xov tooj zoo dua obespokoytes nws yam nyob rau hauv ua ntej thiab cob rau "tiag tiag" los yog "integer".

rooj

Cia tam sim no tham txog qhov chaw nyob ib ncig ntawm peb. Peb nyob hauv ib lub peb-dimensional lub ntiaj teb no, thiab feem ntau ntawm cov khoom yuav tsum tau piav nrog 3 tsis: ntev, dav, qhov siab. Thiab los ntawm muaj lub dimension arrays. Ob-dimensional arrays - ib lub rooj rau cov ntaub ntawv, nyob rau hauv uas txhua lub caij yog muab ntau tshaj ib tug naj npawb, thiab tus ob - kab xov tooj thiab sab tooj. Thaum xa mus rau lub ob-dimensional array yuav tsum qhia kom meej ob lub xov tooj - D [1, 1].

Raws li, qhov no array yuav tsum tau muab khaws cia loj nyiaj ntawm cov ntaub ntawv. Tu siab, nyob rau hauv cov laus programming lus, nyob rau hauv Feem ntau, lub array caij tooj yuav ua xwb tus xov tooj. Yog li ntawd, lub cia ntawm loj ntxhuav, nws ua heev problematic vim lub fact tias ib sab ntawm lub rooj yuav tsum tau tsim ib daim array.

Piv txwv li, piv txwv peb muaj ib lub rooj nyob rau hauv uas cov ntaub ntawv yog sau ntawv mus rau cov menyuam kawm ntawv. Lawv yog: xyoo ntawm yug me nyuam, lub npe ntawm tus hauv chav kawm ntawv.

Nyob rau hauv tej yam tshwm sim, peb yuav tsum tsim ntau arrays, nyob ntawm seb cov kev xav tau. Peb muaj peev xwm tsim ib tug ob-dimensional array ntawm numeric hom rau khw hnub yug thiab cov chav kawm ntawv, thiab lub thib ob array rau khaws cia ntawv nyeem ntaub ntawv (FI). Tab sis nws yog tsis yooj yim. Ua ntej, xeem thiab lub npe, tej zaum koj yuav muaj lis nyias. Secondly, koj yuav tau yooj yim tau tsis meej pem thaum sau tus array nrog ib lub xyoo thiab cov chav kawm ntawv. Yog li ntawd, nws yuav yooj yim rau tsim 4 cais arrays rau ib sab. Pom zoo, nws yog heev cumbersome?

PHP

PHP arrays yuav daws tau qhov teeb meem raws li hais saum toj no. Qhov tseeb yog tias nyob rau hauv no programming lus, koj yuav tau qhia kom meej tsis tau tsuas yog lub hom ntawm cov ntaub ntawv nyob rau hauv lub array, tab sis lub 'meter' hom (Performance index). Nyob rau hauv tas li ntawd, cov ntaub ntawv sib txawv ntawm cov hom tej zaum yuav muaj nyob rau hauv ib array. Tsim ib tug ib-seem array (Yog hais tias koj xav muab ib sab):

• $ Array = array (1989, 1988, ...);

Qhov kev piv txwv tsim ib tug yooj yim array. Qhov Performance index yog tsim tau thiab yog pom tias zero. Hais tias yog, pes tsawg array caij - 1989, thawj - 1988, thiab lwm yam Tab sis li cas yog hais tias peb yuav tsum muab tso rau lub tag nrho cov lus rau hauv ib tug ntau txoj array? Yuav ua li cas yog multi-dimensional PHP array? Qhov no qauv, nyob rau hauv uas txhua lub caij kuj yog ib qho array. Yuav ua li cas lauj tus yam ntxwv rau peb?

$ Rooj = array (

array (1989, "Smith", "John", 9)

array (1988, "Smith", "Peter", 10),

...

);

Yuav ua li cas peb muaj nyob rau hauv lub kawg? Peb muaj ua ntej peb ib tug array hu ua $ rooj, uas kab raws li cov kab nyob rau hauv lub rooj. Yog hais tias kovorit ib array ntawm hais, ces lawv yuav zoo li no:

• $ Rooj [0, 0] = 1989, $ rooj [0, 1] = "Smith", $ rooj [0, 2] = "John", $ rooj [0, 3] = 9.
• $ Rooj [1, 0] = 1988, $ rooj [1, 1] = "Peter", $ rooj [1; 2] = "Peter", $ rooj [1, 3] = 10.

Wherein 0 thiab 3 txhua yog numeric array, thiab 1 thiab 2 - cov ntawv nyeem. Yog hais tias tsim nyog, koj muaj peev xwm ib txwm hloov qhov tsim nyog cov ntaub ntawv nyob rau hauv cov yam hom ntawv thiab hauj lwm ua ke hlwb.