Lwenkqubo ngokwayo ibe nobucukubhede. Okokuqala, ukuba zonke izenzo mayicaciswe gca inyathelo ngenyathelo. Kodwa ndimelwe enjalo, kukho iinkalo eziliqela ukuba kube lula kakhulu impumelelo yale misebenzi ezifuna ukuba kwiprogram ( "Pascal", "C", "assembler" - nokuba asetyenziselwa ntoni ulwimi). Enye yezi zixhobo kukudala nemijikelo.
Ukubaluleka imijikelo iinkqubo
Yintoni umjikelezo? Kutheni efunekayo yaye yintoni iingenelo wenkqubo xa usebenzisa nto? Umjikelo wenkqubo yinxenye ebalulekileyo noshowo nkqubo, nto leyo evumela ukuba imishini ekwenziweni inani elithile ngezenzo, ukuba ukuthotyelwa parameters lusekiwe. Ngoko ke, ngomzekelo elula lomjikelo yomsebenzi - podnesenie inani elithile ukuya emandleni. Akukho mfuneko ukumisela imiqolo ukuya kude akayi kuba ngokwaneleyo, kuba oomatshini nako konke kwenziwa ngokuzenzekela nayo. Kulo mkhuba yemijikelo kwakhona ungagcina elininzi ixesha kunye nomgudu, ngoko akuyomfuneko lonke ixesha kwaye onke amanyathelo ukubhalisa ikhowudi usebenzisa umjikelo. Simply ngenisa izinto iguquguqukayo uqale ukuphunyezwa. Kodwa njengoko inkqubo eyakhelwe-cycle? Okanye ngaphezulu? Ngokwabo embodiments zomjikelo kakhulu eninzi - ulwazi malunga nencwadi lwezobuchwepheshe, "NjengoPascal," siza kuqwalasela okanye "assembler". Ngoko ke, nje ngenjongo yokwazisa ibattery ukunika icebo theoretical ukusetyenziswa ezimbili ethandwa:
- Cycle ne postcondition.
- Yomtya nge sibalulekile.
Bonke abanye ubukhulu enkulu iinguqulelo zazo kunye kwiimeko ezithile, ngoko ke kufuneka ingqalelo kwimeko kwaye ekufezekiseni iinjongo ezithile. Okwangoku, makhe nisinga kakhulu ethandwa. Imijikelezo ezahlukeneyo kunye zangaphambili kunye postconditions? Nantsi yomtya kunye njengomqathango:
ngexesha «imeko» ukwenza «ikhowudi»
Umjikelo isakhiwo sethiyori jikelele nge postcondition
Olu hlobo lwe khowudi yokubhala xa umjikelo yomsebenzisi kunye neendleko nokuphunyezwa postcondition komzimba. Ngophanya nje lweliso, kubonakala kuyinqaba inokuba: ngokwenene, kutheni ubeke imeko emva kokuphunyezwa ikhowudi? Kodwa akukho nto engaqhelekanga apho: inkalo yale fom kukuba ikhowudi esiqhutywa kungakhathaliseki nokuba imiqathango ithotyelwe okanye azenziwa. Kodwa ekuhambeni kwexesha 1 kuphela. Uya kwandula landela uvavanyo, nokuba zonke, njengoko kufuneka, okanye hayi. Kwaye kungekho iimeko zomzimba olwaneleyo kumjikelo ayiyi kuhoywa. Le yinto ebaluleke kakhulu kwaye iluncedo, nto leyo iba yomjikelo postcondition. Kulo mzekelo koko waxelelwa ukuba nalapho ungabona i zozalisekiso zaveza apha? Nanku umzekelo yomjikelo postcondition:
phinda
"Umthetho"
de «Conditions»
Jikelele senkolelo umjikelo nesisekelo njengomqathango
Kodwa ukhetho kakhulu ethandwayo oku ngqo. peculiarity yayo siyifumana kukuba kule ngokubulawa imeko kuyimfuneko, ngaphandle le khowudi nanini babulawa. Ngokuqhelekileyo, le khowudi isikali kakhulu kwaye isebenze nempembelelo ogcweleyo elibi yokusebenza computer. Ngoko ke, wasebenzisa kakhulu isicwangciso wengcibi: uninzi izicwili ikhowudi ababekwe ephambuka okanye iiklasi ngabanye isibheno kufika kanye ngexesha mathuba ekunene. Lonke elo xesha le khowudi, kodwa musa ukusebenzisa ikhompyutha. Esi sikimu ikuvumela ukugcina amandla liqhube ukuphumeza inkqubo okanye ezinye iinkqubo.
ukuphunyezwa Practical ngeelwimi ezahlukeneyo kweenkqubo
A amagama ambalwa malunga ukusebenza okubonakalayo kweli mijikelo. Kufuneka kuqatshelwe kuqala zonke konga ixesha, zombini umsebenzisi kunye Ndingumqondisi. Ngomhla wesibini kwathiwa, kutheni, kutheni amagama ambalwa ukuba uthini ngumthengi. Isibakala sokuba ukwahlulwa ibe abahlukene ivumela software ukuba ukulayisha ngokukhawuleza kwaye ukubaleka, kwaye ngokufanelekileyo, umsebenzisi uya kukuvuyela ukusebenzisa software kuphela kakhulu. Ngaphezu koko, le ndlela, xa ikhowudi egcinwe kumjikelo okanye udidi eyahlukileyo (elikholisa ukuba ivela emzimbeni), kwaye ivumela ukusebenza ukusebenza. Kufuneka ungenise ingxelo ngesantya iiseli kwimemori ngamnye. Ngoko ke, ukuba yonke into yenziwe ngesandla, bekuya kufuneka ukufumana nganye kwaye kukho ungeno efanelekileyo. A loop ivumela izihlandlo eziliqela okanye iqela yokunciphisa imfuneko ukwenza yonke into ngokwakho. Kwaye isusa into zabantu, nto leyo enokukhokelela ekubeni iiyure kufuneka ukukhangela ikhowudi eziyingxaki.
isiphelo
Ngoko ke, UPawulos zonke ezibhaliweyo, singatsho ukuba umjikelo kunye postcondition okanye pre yenza indlela elula ukonga imali ngaphandle kokubiza umgangatho. Kwaye xa ubhala iinkqubo ezintsonkothileyo, yenye bahlobo basenyongweni umdwelisi nkqubo, ukunceda ukuba wenze ikhowudi lula ukwenza kunye nokufunda. Ngoko ke, xa ubhala ikhowudi yabo ayiyi bangafuni ukusebenzisa yomjikelo postcondition okanye yangaphambili - zenzelwe ngokukodwa ukuba kube lula inkqubo indalo software, yaye uya kusebenza kuye - ukuba basebenzise eli thuba.