Java Array. Arrays nyob rau hauv Java. Java rau beginners

Array (Eng. Array) yog ib tug haib lub cuab tam uas tso cai rau koj mus ua hauj lwm nrog loj nyiaj ntawm cov ntaub ntawv. Obviously, Yog hais tias koj ua hauj lwm nyob rau hauv koj cov cai qhov chaw koj xav kom txuag, piv txwv li, 100 qhov tseem ceeb, ces ua tsawg kawg qhov no yog ntxhais Khana-as rau cov tib tooj ntawm cov tsiaj ntawv. Ib tug array tso cai rau koj los khaws ib tug loj tus naj npawb ntawm qhov tseem ceeb nyob rau hauv ib tug ib lub npe, thiab chaw nyob rau lawv ntawm qhov tsim nyog index. Lub tswvyim yog lub pobzeb ntawm arrays nyob rau hauv Java txoj kev tshawb no kawg rau beginners. Tom qab tag nrho, lawv yog lub hauv paus rau ntau cov ntaub ntawv lug.

Vim hais tias Java yog, saum toj no tag nrho, lub PLO, muab piv nrog arrays nyob rau hauv lwm yam lus java programming array muaj ib qhov txawv feature - lawv yog sawv cev raws li khoom. Cov lwm zoo, nws yuav rhuav tshem qhov yuav tsum tau mus soj ntsuam cov purification ntawm lub cim xeeb, vim hais tias nws yog tso tawm tau.

Creation thiab manipulation ntawm ib-seem arrays

Ib tug ib tug-dimensional array yog ib tug classic thiab Java array yog ib tug sau ntawm lwm yam kev lub npe hais, txhua yam uas raws li ib tug kev index. Txoj kev mus rau tshaj tawm ib tug array yog qhia nyob rau hauv daim duab hauv qab no.

Chiv tshaj tawm hais tias lub hom Java array, uas qhia txog cov hom ntawm qhov tseem ceeb uas yog cia nyob rau hauv nws. Qhov no yuav ua tau tej siv tau nyob rau hauv lub Java cov ntaub ntawv hom. Tom ntej no tuaj lub npe ntawm tus array thiab cov square nkhaus qhia cov compiler hais tias tus nce mus nce los yog ib tug array. Xyuam xim rau ib qho tseem ceeb fact. Cov pab pawg yuav tsum muab tso rau tom qab rau lub hauv paus hom ntawm cov array, thiab tom qab lub array lub npe. Tom qab lub sib npaug zos kos npe rau hais neeg teb xov tooj tshiab, pib qee ntawm cov cim xeeb rau lub array (tib yam li nyob rau hauv cov ntaub ntawv ntawm tej khoom), hom ntsiab yuav tsum tau muab cia rau therein (yuav tsum tau tshaj rau lub hauv paus hom tshaj tawm hais tias saum toj no), thiab, thaum kawg, tus xov tooj qhia nyob rau hauv pab pawg.

Lub numbering hais nyob rau hauv lub Java array pib ntawm 0. Yog li ntawd, lub Performance index ntawm cov thawj lub caij nyob rau hauv lub array yog sib npaug zos rau 0, thiab lub thib rau - 5. xa mus rau ib lub caij ntawm lub array, xws li lub thib tsib, qhia kom meej lub npe ntawm tus array yog txaus thiab lub Performance index nyob rau hauv square nkhaus tom ntej no mus rau lub npe . Yog li ntawd nws yog ua tau npe raws li tus nqi ntawm lub caij, thiab tshem tawm cov nws. Txawm li cas los, ib tug yuav tsum tau ceev faj, vim hais tias yog koj kis tau tus index uas muaj yog tsis muaj caij, ib qho yuam kev tshwm sim.

Multidimensional Arrays nyob rau hauv Java

Multi-dimensional arrays yog ib tug series ntawm ib-seem, nyob rau hauv lwm yam hais hais arrays. Nyob rau hauv lwm yam lus, cov arrays ntawm arrays. Qhov yooj yim ntawm no yog ob-seem. Lawv piv txwv li peb yuav sim kom to taub lub tswvyim. Rau clarity, daim duab hauv qab no qhia tau hais tias cov syntax thiab ib daim duab piav txog cov qauv ntawm cov two-dimensional array.

Raws li koj tau pom, lub syntax yog tsis ntau sib txawv los ntawm ib tug-dimensional arrays. Cia saib cov qauv. Nyob rau hauv thawj qhov chaw, peb tau pom cov nkhaus nyob rau hauv lub 5 ntsiab. Cov ntsiab yog tsis muaj dab tsi tab sis ua tim khawv rau ib tug neeg arrays. Qhov luaj li cas ntawm txhua tus ntawm lawv txiav txim los ntawm tus xov tooj nyob rau hauv lub thib ob koov. Nyob rau hauv qhov tseeb, ib tug analog ob-dimensional arrays nyob rau hauv kev kawm txog zauv yog cov matrix. Nco ntsoov tias nyob rau hauv tas li ntawd mus rau lub ntsiab cais chaw, qhov twg tus nqi ntawm cov array ntev (ntev) yog muab cia rau hauv lub faib lub cim xeeb. Feem ntau, cov ua hauj lwm nrog multi-dimensional arrays yog nqa tawm los ntawm kev nested loops.

lus arrays

Lub ob-dimensional array yog ib qho array ntawm arrays. Qhov no peb twb pom. Tab sis seb arrays yog muaj nyob rau ntawd, muaj ntau lengths? Cov lus teb no - yog, lawv ua tau. Yuav kom qhov no kawg, Java muab lub sij hawm los mus tshaj tawm ib ob-dimensional array nyob rau hauv ib tug tshwj xeeb txoj kev. Piv txwv li, peb xav tau los ua ib tug ob-dimensional array uas yuav cia ib tug peb-dimensional array ntawm ntev 2, 3 thiab 4, ntsig txog. Nws tshaj tawm hais tias raws li nram no:

intarr [] [] = newint [3] [];

Thov nco ntsoov tias peb tsis qhia kom meej rau tus xov tooj nyob rau hauv lub thib ob parenthesis. Txiav txim qhov loj ntawm lub array arr yog raws li nram no:

arr [0] = tshiab rau cov menyuam [2];

arr [1] = tshiab rau cov menyuam [3];

arr [2] = newint [4];

Xa mus rau cov yam khoom ntawm index 0 ntsiab lus mus rau tus thawj array, peb tshaj tawm nws mus rau lub dimension ntawm 2. Lub caij index 1 yuav tsum tau ceev cia lub dimension array 3, thiab hais txog. Nws yog yooj yim zoo nkauj.

Lwm syntax java array tawm

Initialize cov arrays yuav tau ncaj qha mus thaum lawv tsim. Nws yog yooj yim zoo nkauj.

Them mloog mus rau cov tawm thiab arrays jerseyNumber playerName.

Nyob rau hauv cov ntaub ntawv ntawm ob-dimensional arrays ntawm no tshaj tawm yog raws li nram no:

rau cov menyuam [] [] arr = {

{1, 2, 3},

{4, 5, 6},

{7, 8, 9}

}

Ua li no, es tsis txhob ntawm tus tshiab xov tooj qhib brace, nyob rau hauv uas ib tug tsis nco qab yog ib daim qhia txog ntawm tag nrho cov ntsiab. Java nyob rau hauv cov ntaub ntawv no tau allocates nco rau lawv thiab indexes raws li lawv.

Pab cov chav kawm ntawv Arrays

Mus ua hauj lwm nrog xws li cov chaw raws li arrays nyob rau hauv Java, nyob rau hauv lub java.util pob muaj ib tug tshwj xeeb hauv chav kawm ntawv ntawm lub Arrays, uas muab ib tug ntau yam ntawm zoo li qub txoj kev, zoo heev yooj yim ua hauj lwm nrog lawv. Ib daim ntawv teev cov ntsiab txoj kev yog nyob rau hauv daim duab hauv qab no.

Cia peb kawm txog tej co lus tseem ceeb Java array txoj kev:

- copyOf (array ntev) - rov ib daim qauv ntawm cov kis array coj ntev. Yog hais tias kis tau yog ntev tshaj li lub thawj array, ces tag nrho cov "ntxiv" hais yog lawm ua tus sau nrog lub neej ntawd tus nqi (0 yog hais tias tus yooj yim ntaus, thiab thov, yog hais tias tus reference).

- copyOfRange (array, thawj Performance index, lub tom kawg index) - tsis qhia nyob rau hauv daim duab, tab sis ib tug pab tau txoj kev. Nws cov ntawv luam ntawm cov dhau array, defining tsim nyog indexes los ntawm tus thawj kom kawg.

- tsi (array) - sorts lub ntsiab ntawm lub array nyob rau hauv ascending thiaj.

- sau (array tus nqi) - nyob ib array coj tus nqi kis.

- binarySearch (array tus nqi) - rov index los ntawm cov uas lub caij nrog cov coj tus nqi muab cia rau hauv lub sorted array kis. Yog hais tias qhov no caij uas ploj lawm, qhov tsis zoo pes tsawg yog xa rov qab.

Txij li thaum txoj kev yog zoo li qub, yuav tau hu rau lawv tsis xav tau los ua ib tug piv txwv ntawm cov chav kawm ntawv Arrays. Lawv hu ua ncaj qha los ntawm nws: Arrays.sort (arr).

xaus

Peb tau saib lub tseem ceeb tshaj plaws yam hais txog lub array, thiab rau cov neeg uas cia li pib mus kawm Java rau beginners, qhov no yog txaus rau ib tug to taub yooj yim ntawm xws li ib qhov chaw, raws li ib tug array, thiab qhov yooj yim kev ua hauj lwm nrog nws. Ntawm cov hoob kawm, txoj kev xyaum yuav muab ib tug ntau dua kev nkag siab ntawm no lub cuab tam. Yog li ntawd, tsis txhob yuav tub nkeeg mus ua ib ce, manipulating arrays nyob rau hauv ntau txoj kev.

Array Java pab hauv chav kawm ntawv twb tau muab siv nyob rau hauv "kev sib ntaus los" tej yam kev mob, li ntawd nws yog pom zoo kom pib kawm los tsim tag nrho cov yooj yim ua hauj lwm nrog arrays manually.