Kuyini Pascal. UHlelo e Pascal

Kuyini Pascal? Baningi impela abantu ukubuza le nkinga. Ngokuyinhloko, lezi abantu abasebenzisa ikhompyutha ezingeni eliyisisekelo. Pascal - lokhu ingenye ethandwa kakhulu izilimi izinhlelo. Funda ke, ngokuvamile esikoleni esiphakeme noma izifundo lokuqala amanyuvesi. Kuthathwa ngesisekelo kwezinye izilimi eziningi zokuhlela.

indaba

Kuyini Pascal, sithole aphume. Manje uqhubeke ngqo umlando ukuvela nokwakheka kwalo. UMdali Ulimi - Niklaus Wirth. Lwakhiwe esikhathini kusuka ngo-1968 kuya 1969. Pascal ekudaleni umqondo weza kuye ngemva kokuba semhlanganweni ikomiti ekhethekile on ukuthuthukisa ulimi. Kuyini Pascal, kuyathakazelisa program eminingi imfundamakhwela. Leli gama ngolimi yethiwa isazi sesayensi esidumile French Blaise Pascal, okuyinto ikakhulukazi idume ukudalwa umshini mechanical, ngokufingqiwe izinombolo ezimbili.

Kukhululwa incwadi yokuqala yalokho Pascal, uvele 1970. Bakhuluma ngoZiqu-injongo eyinhloko ukudala lolu limi, ezifana kahle, okuyinto wayeyobe enikela kakhulu amakhono izinhlelo nedatha zesakhiwo.

Ulimi ukuqaliswa

• UCSD Pascal. Lolu hlelo yasungulwa ngo-1978. Kwakubonakala port yesakhi elikuvumela khomba ephathekayo, futhi manje ukuhlelwa uhlelo yokuqala, nokunye. Kamuva UCSD yaba isisekelo sezinguqulo implementations eziningi okwalandela Pascal.
• Into Pascal. UHlelo e Pascal idonse njalo ochwepheshe abaningi abasha. Ngo-1986, i-Apple wadala into isandiso ulimi. Iqembu ukwenza ekuthuthukisweni, kokuxhumana "Ubaba" ka Pascal.
• Turbo Pascal. Le nguqulo yokuqala ye-IDE wabonakala ngo-1983. Borland kwaba nkampani ukuthi waziphatha ukuthuthukiswa lokhu kusebenza. Nokho, kufanele kuphawulwe ukuthi Turbo Pascal okuningi lathathwa Odject Pascal, futhi bebonke, lezi implementations ayefana. UHlelo e Pascal unesithakazelo ne-Microsoft. Cishe ngesikhathi esifanayo, abadedela inguqulo yabo ulimi into esekelwe Pascal. Wayengakwazi uthole ukusatshalaliswa kwenqwaba, futhi ngokushesha kwaba ukhohliwe. Ngemva kwalokho, ukuqaliswa ngokuthi Into Borland sika Pascal.
• Into Pascal namuhla. Isinyathelo esibaluleke kunazo zonke emlandweni Pascal kuyinto isivuno implementations khulula. Babehlanganisa konke okuhle kusuka kwamanye imixhantela eminingi. Zinikeza kwedivayisi kakhulu nge izinhlelo kakhulu yokusebenza.

Izici

Ukujwayeleka ne Pascal ulimi kuyadingeka ukuze uqale nge izici zayo. Chief phakathi kwabo - the ukuthayipha eqinile futhi khona izinhlelo olwakhiwe. Pascal - ngowokuqala yalolu hlobo ulimi. Wacabanga unjiniyela, ulimi kumele neqhaza izinhlelo ukuyalwa kusukela ekusungulweni kwayo kwakushiye ngaphandle ngangokunokwenzeka ezihlukahlukene amaphutha wokuma, kanye samanje interface enembile. Kuyini Pascal, futhi iziphi izici zako ezisemqoka - izimpikiswano eziyinhloko of interest Wabasaqalayo. Ulimi oluphakeme elula ngisho saqala.

Nokho, ekuqaleni, ulimi enezinto eziningi ezingezinhle. Chief phakathi kwabo: ukungakwazi ukusebenza inkumbulo ashukumisayo, umtapo iDemo IO, ukungabi nemali ukusebenzisa imisebenzi wadala ngezinye izilimi, nokunye. Kuyini Pascal, esilulimi lwaso ulula, ekuqaleni '80s, ochwepheshe abaningi baye bafunda. Nokho, akuwona wonke Kwathi ukunambitha. Abanye ochwepheshe ngisho wabhala izihloko abangu ngesineke ngokuningiliziwe mayelana yokuntuleka zolimi ngalunye.

Amaphutha kanye uzikhuza

Njengezinye izilimi eziningi zokuhlela, Pascal inama akuzona kuphela kodwa futhi yokuntula sina. Kumele ukuthi kancane kancane Onjiniyela benenkinga nemibi, kodwa awalona njalo.

Njengoba okuningi njengoba kungase kubonakale kuyinto encane, kodwa akuyona kwamaphutha ulimi into engavamile isiza program e ukuqeqeshwa. Ngaphezu kwalokho, Pascal in the 80s kwaba igxathu elikhulu lentuthuko uma ziqhathaniswa Fortran, ngaleso sikhathi wafunda kulezi zifiki. Ikakhulukazi Fortran ayenezinkinga ngaphezulu. Esikhathini esifushane kakhulu isikhathi, Pascal uye wakwazi ukuba abe ulimi esiyinhloko efundisa izikole eziningi namanyuvesi. Ngezinye kwesisekelo salo ezakhiwa izinhlelo eziningi.

isakhiwo

Mayelana Pascal ungabhala eziningi, kodwa kufanele uye ngqo inqubo izinhlelo. Ngasinye isicelo e Pascal iqala elingukhiye (Uhlelo). Ngokushesha ngemva ecacisiwe igama uhlelo, bese ukubeka ";". Kwesinye isikhathi lokhu kungadingeki. Ngemva igama, ungacacisa uhlu lwamafayela zangaphandle ukuthi izodlala nemingcele. Ngemva kwalokho eza esibaluleke kunazo uhlelo - umzimba wakhe. It sinetigaba izincazelo constants, izinhlobo, eziguquguqukayo, izinqubo kanye nemisebenzi. Ngemva kwabo kukhona block ezitatimende - entry phuzu. opharetha iyunithi itholakala phakathi angukhiye iqale futhi iphele. isitatimende ngasinye ahlukaniswe isemikholoni. Ukuqeda uhlelo isebenzisa iphuzu lapho ibekwa ngemva emzimbeni.

amamojuli Isicelo

Ukuze module isicelo ikhodi Uhlelo kumele kube khona isikhangiso ke. Ukuze enze isimemezelo esinjalo, ungasebenzisa imiyalelo uxhumano, okuyinto elisemqoka USEBENZISA. Ngemva kwakhe, amagama amamojuli ukuba axhunyiwe. Imiyalelo langena ngokushesha ngemva unhlokweni noma esigabeni esibonakalayo.

Ezinye implementations Asisekeli amamojuli ulimi, izinguqulo ikakhulukazi amadala. Abakwazi ihlukaniswe ezimbili izinhlobo: isofthiwe nokusekelwa. Eyokuqala ekhona ohlelweni iqala uhlelo elisemqoka. Eyesibili kuhlanganisa eziguquguqukayo, constants, izinhlobo nokunye, ingasetshenziswa kweminye amamojuli.

izimpawu zokuloba

-syntax Pascal kudinga bawuhloniphe.

• Ikhefanangqi. Kubekwe ekupheleni kwesihloko, ngemva incazelo eziguquguqukayo. opharetha ahlukaniswe ngayo. Awukwazi ukusebenzisa phambi ekupheleni elisemqoka.
• Ikhefu. Isetshenziswa njengesici isihlukanisi ezihlukahlukene uhlu.
• Point. Kubekwe ekupheleni umzimba uhlelo (emva izwi ukuphela).

-syntax okunjalo eqinile nakho ngeke kusize kuyadingeka ngoba ikhompyutha kubhekwa usebenzisa uhlelo lokusebenza. Endabeni umlingisi ayilungile ubonisa nephutha. Uma isemikholoni uba isihlukanisi isitatimende, opharetha ubhekwa yonke umbhalo phakathi iphuzu elilodwa kanye iphuzu okwalandela. Endabeni le nepostanovki uphawu phakathi opharetha, lolu hlelo luyoba uzithatha eyodwa futhi esikhiqiza nephutha.

ulimi Pascal ikuvumela ukufaka imibono. Bakhonza njengabashumayeli incazelo ukuze ikhodi hlelo. Ungasebenzisa isiRashiya. On uhlelo amazwana musa ukuveza noma yiphi umphumela.

Ngo Pascal, ungabhala kokubili ezincane futhi osonhlamvukazi. Kukhethwa isesikhathini uMklami.

ukugxekwa

Njengoba kakade kushiwo, ukuthandwa olukhethekile Pascal wangena 1980-1990, kodwa kwakukhona baxgeki bebheka ulimi engenangqondo. Ngokombono wabo, kuba ezifanele kuphela ukuqeqeshwa. Ikakhulukazi ukugxekwa eqaphelekayo kuchazwe esihlokweni esithi "Kungani Pascal akuyona ngolimi lwami ozithandayo izinhlelo." Wawuthi kaBrian Kernighan - omunye Onjiniyela C. Kwakungemva sihloko Pascal baqala washintsha kakhulu ube umuntu ongcono.

Naphezu kwazo zonke lezo amaphutha, ngokucindezelwa kakhulu ku Pascal sengqondo sokunganaki of program eminingi.