Yuav ua li cas yog Pascal. Programming nyob rau hauv Pascal

Yuav ua li cas yog Pascal? Kuj muaj ntau tus neeg nug no qhov teeb meem. Yeej, cov no yog cov neeg uas siv ib lub computer ntawm ib tug yooj yim theem. Pascal - qhov no yog ib qho ntawm feem nrov programming lus. Kawm nws, feem ntau yog nyob rau hauv high school los yog nyob rau hauv thawj chav kawm ntawm universities. Nws yog suav tias yog lub hauv paus rau ntau ntau lwm yam programming lus.

zaj dabneeg

Yuav ua li cas yog Pascal, peb tau pom tawm. Peb tam sim no mus ncaj qha mus rau lub keeb kwm ntawm nws cov emergence thiab kev loj hlob. Language Creator - Niklaus Wirth. Nws yog tsim nyob rau hauv lub sij hawm ntawm 1968 mus rau 1969. Pascal tsim lub tswv yim tuaj rau nws tom qab mus kawm ib tug tshwj xeeb pawg neeg nyob rau hauv txoj kev loj hlob ntawm cov lus. Yuav ua li cas yog Pascal, nws yog nthuav kom ntau novice programmers. Qhov no lub npe yog lus lub npe hu ua tom qab tus naas ej Fabkis tus paub txog Blaise Pascal, uas yog tshwj xeeb yog nto moo rau tus creation ntawm ib tug txhua yam tshuab, sau ua ke ob tug zauv.

Tus thawj ntawv ntawm dab tsi Pascal, tau tshwm sim nyob rau hauv 1970. Lawv tham txog lub hom phiaj tseem ceeb ntawm kev tsim cov lus no, xws li ua hauj lwm zoo, uas yuav pab rau yav tom ntej programming kev txawj ntse thiab cov ntaub ntawv structuring.

Cov kev siv lus

• UCSD Pascal. Qhov no system yog tsim los pab nyob rau hauv 1978. Nws nyob compiler chaw nres nkoj uas tso cai rau koj mus rau code portable, thiab muaj peev xwm tam sim no yuav edited tus thawj system, thiab hais txog. Tom qab ntawd UCSD los ua lub hauv paus rau ntau yam tom ntej Pascal implementations.
• Nruas Pascal. Programming nyob rau hauv Pascal yeej ib txwm nyiam cov hluas tub txawg. Nyob rau hauv 1986, Kua tsim khoom extension lus. Cov pab pawg neeg yog koom nyob rau hauv txoj kev loj hlob, kev noj kev haus nrog rau cov "txiv" ntawm Pascal.
• Turbo Pascal. Tus thawj version ntawm lub IDE nyob rau hauv 1983. Borland yog lub tuam txhab uas twb koom nyob rau hauv txoj kev loj hlob ntawm no siv. Txawm li cas los, nws yuav tsum tau muab sau tseg hais tias Turbo Pascal ntau borrowed los ntawm Odject Pascal, thiab nyob rau hauv Feem ntau, cov implementations twb zoo sib xws. Programming nyob rau hauv Pascal xav thiab Microsoft. Yuav luag nyob rau tib lub sij hawm, lawv tso lawv tus kheej version ntawm tus kwv lus raws li nyob rau hauv Pascal. Nws yuav tsis tau txais cov loj muab faib rau, thiab tau sai tsis nco qab lawm. Tom qab, qhov kev siv ntawm Borland tus hu ua Nruas Pascal.
• Nruas Pascal niaj hnub no. Qhov tseem ceeb tshaj kauj ruam nyob rau hauv lub keeb kwm ntawm Pascal yog lub tawm los ntawm free implementations. Lawv muaj tag nrho cov qhov zoo tshaj plaws ntawm ntau lwm yam dialects. Lawv tuaj rau yav tom ntej compatibility nrog rau feem ntau kev khiav hauj lwm systems.

nta

Kawm paub txog cov lus Pascal yog tsim nyog los pib nrog nws cov nta. Chief ntawm lawv - lub strictest typing thiab muaj cov cob qhia programming. Pascal - tus thawj ntawm qhov no zoo ntawm cov lus. Nws xav tias tus tsim tawm, cov lus yuav tsum pab disciplined programming, txij li thaum nws cais ntau li ntau tau ib tug ntau yam ntawm syntax yuam kev, raws li tau zoo raws li tam sim no ib tug intuitive interface. Yuav ua li cas yog Pascal, thiab dab tsi yog nws cov ntsiab nta - lub ntsiab teeb meem ntawm kev txaus siab rau beginners. Cov lus yog haum yooj yim txawm rau ib tug beginner.

Keeb xeeb, Txawm li cas los, cov lus muaj ib tug xov tooj ntawm disadvantages. Chief ntawm lawv: lub cev tsis ua hauj lwm nrog dynamic nco, luv luv rhuav tshem cov ntaub ntawv, tsis muaj nyiaj mus khiav lub zog tsim nyob rau hauv lwm yam lus, thiab thiaj li nyob. Yuav ua li cas yog Pascal, uas nws cov lus yog heev yooj yim, nyob rau hauv thaum ntxov '80s, muaj ntau cov kws txawj tau kawm. Txawm li cas los, tsis yog txhua txhua ntawm nws tuaj mus saj. Ib cov kws txawj txawm sau cov khoom uas tau pleev xim rau hauv kom meej txog txhua tsis muaj lus.

Flaws thiab kho lawv

Zoo li ntau lwm programming lus, Pascal boasts tsis tau tsuas yog qhov zoo tiam sis kuj loj disadvantages. Nws yuav tsum tau hais tias maj mam developers chav nrog disadvantages, tab sis nws yog lawv ua tsis tau ib txwm.

Raws li ntau li ntau nws yuav sound, tab sis nws tsis yooj yim dua lus tsis pab programmers nyob rau hauv txoj kev kawm. Nyob rau hauv tas li ntawd, Pascal nyob rau hauv lub 80s yog ib tug lossis loj kauj ruam rau pem hauv ntej nyob rau hauv kev sib piv nrog Fortran, uas nyob rau ntawm lub sij hawm kawm cov tuaj tshiab. Tshwj xeeb tshaj yog Fortran muaj teeb meem ntau. Nyob rau hauv ib tug heev luv luv lub sij hawm ntawm lub sij hawm, Pascal tau muaj kev tswj los ua lub ntsiab lus rau cov kev qhia nyob rau hauv ntau cov tsev kawm ntawv thiab universities. Thaum nws puag tau tsim heev heev cov kev pab cuam.

qauv

Hais txog Pascal koj yuav sau ib tug ntau, tab sis nws yuav tsum mus ncaj qha mus rau lub cajmeem txheej txheem. Txhua daim ntawv thov nyob rau hauv Pascal pib nrog cov lo lus tseem ceeb (Program). Tam sim ntawd tom qab qhov kev cai tswjhwm kev pab cuam lub npe, thiab ces muab tso rau ";". Tej zaum qhov no yog tsis yuav tsum tau. Tom qab lub npe, koj yuav qhia ib daim ntawv teev lwm cov ntaub ntawv uas yuav ua si tsis. Tom qab ntawd los tseem ceeb tshaj plaws nyob rau hauv qhov kev pab cuam - nws lub cev. Nws muaj seem kev qhia txog ntawm constants, hom, ntau yam, cov txheej txheem thiab kev khiav dej num. Tom qab lawv muaj ib tug block ntawm cov nqe lus - lub nkag kis. neeg teb xov tooj chav tsev yog nyob nruab nrab ntawm lub keywords pib thiab qhov xaus. Txhua daim ntawv qhia yog sib cais los ntawm ib tug semicolon. Yuav kom xaus qhov kev pab cuam siv ib tug taw tes uas yog muab tso rau tom qab lub cev.

Daim ntawv thov modules

Rau daim ntawv thov module nyob rau hauv qhov kev pab cuam code yuav tsum tam sim no ib tug advertisement rau nws. Yuav kom ua xws li ib tug tshaj tawm, koj muaj peev xwm siv kev twb kev txuas cov lus qhia, uas yog ib tug lo lus tseem ceeb siv. Tom qab nws, cov npe ntawm modules yuav tsum tau kev cob cog rua. Cov lus qhia nkag mus hauv tam sim ntawd tom qab lub header los yog nyob rau hauv lub interface seem.

Ib txhia implementations tsis txhawb cov lus modules, tshwj xeeb tshaj yog cov laus versions. Lawv yuav tsum tau muab faib mus rau hauv ob hom: software thiab kev pab txhawb nqa. Tus thawj yog tam sim no nyob rau hauv qhov kev pab cuam yuav pib nrog lub lo lus tseem ceeb kev pab cuam. Qhov thib ob muaj xws li ntau yam, constants, hom thiab thiaj li nyob, yuav siv tau nyob rau hauv lwm yam modules.

punctuation

Pascal syntax yuav tsum tau nruj ua raws cai.

• Semicolon. Tso rau ntawm lub kawg ntawm lub header, tom qab qhov kev piav qhia ntawm lub zog. tswv sib cais los ntawm nws. Koj muaj peev xwm siv tsis tau rau pem hauv ntej ntawm lub lo lus tseem ceeb kawg.
• Tsis nco qab. Siv raws li ib tug separator nyob rau hauv ib tug ntau yam ntawm cov npe.
• Point. Tso rau ntawm lub kawg ntawm qhov kev pab cuam lub cev (tom qab lo lus kawg).

Tej txhav syntax yog tsim nyog vim hais tias cov computer yog suav tias yog yuav tsum tau executing hauv daim ntawv thov. Nyob rau hauv cov ntaub ntawv ntawm tsis yog cim qhia ib qho kev ua yuam kev. Yog hais tias ib tug semicolon ua raws li ib daim ntawv qhia separator, qhov tooj yog xav tau tag nrho cov phau ntawv ntawm ib tug taw tes thiab lub tom ntej point. Nyob rau hauv cov ntaub ntawv ntawm lub cim nepostanovki ntawm tswv, qhov kev pab cuam yuav coj lawv ib tug thiab ua ib qho yuam kev.

Pascal lus tso cai rau koj mus tau ntxig cov lus. Lawv pab raws li tus neeg qhia qhov kev pab cuam cov cai. Koj siv tau cov Lavxias teb sab lus. Nyob rau qhov kev pab cuam cov lus tsis tsim tej nyhuv.

Nyob rau hauv Pascal, koj muaj peev xwm sau ob lowercase thiab loj tsiaj ntawv. Cov kev xaiv yog mus txog rau lub programmer.

thuam

Raws li twb tau hais, qhov tshwj xeeb muaj koob meej ntawm Pascal tuaj nyob rau hauv 1980-1990, tiam sis muaj critics uas xam tau tias yog frivolous lus. Nyob rau hauv lawv pom, nws yog tsim tsuas yog rau cov kev kawm. Tshwj xeeb tshaj yog tseem ceeb thuam tau piav nyob rau hauv tsab xov xwm "Yog vim li cas Pascal tsis yog kuv nyiam programming lus." Nws twb sau los ntawm Brian Kernighan - ib qho ntawm lub developers ntawm C. Nws yog tom qab tsab xov xwm Pascal pib tiag hloov rau lub zoo dua.

Txawm tias tag nrho cov shortcomings, feem ntau pressing rau Pascal xws li tus cwj pwm ntawm ntau programmers.