Ukuhlela ngokwayo angadida. Okokuqala, ukuthi zonke izenzo amaKristu okufanele lelipelwe step by step. Kodwa nge udingeka kangaka, zikhona izici eziningana ukuthi kakhulu lula ekuzuzweni kwemiPhumela imisebenzi kudingeka uhlelo ( "Pascal", "C", "assembler" - kungakhathaliseki ukuthi ulimi lusetshenziswa). Enye yalezi amathuluzi ukudala imijikelezo.
Ukubaluleka izinhlelo imijikelezo
Uyini umjikelezo? Kungani idingeka futhi yini izinzuzo zokuba Unicode lapho uyisebenzisa? Umjikelezo eqakathekileko isakhi Uhlelo, okuyinto ikuvumela ukuba ukushintsha ekukhishweni inombolo ethile yezenzo, inqobo nje uma kuhambisana imingcele aqine. Ngakho, isibonelo elula lomjikelezo umsebenzi - podnesenie inani elithile emandleni. Asikho isidingo ukuba linqume imigqa kuze kube ngeke kwanele, ngoba imishini ningakwazi nonke kwenziwe ngokuzenzakalela ne-ke. Umkhuba imijikelezo futhi ungagcina isikhathi esiningi nokuzikhandla, ngakho-ke asikho isidingo njalo futhi zonke izinyathelo ukubhalisa ikhodi usebenzisa umjikelezo. Vele ufake eziguquguqukayo iyashintsha bese uqala kokusebenza. Kodwa njengoba uhlelo esakhelwe umjikelezo? Noma nakakhulu? Ngokwabo embodiments lomjikelezo impela eningi - ulwazi incwadi mayelana nezinhlelo, "Pascal," sizoxoxa noma "assembler". Ngakho-ke, ngenxa nje zokwaziswa ukuqaqa ukunikela isikimu ezincwadini ukusetshenziswa ezimbili ethandwa kakhulu:
- Cycle nge postcondition.
- Loop nge umbandela.
Zonke abanye njengabakhulu ngokwezinga elikhulu yokwahlukahluka yabo futhi ezindabeni ezithile, ngakho kufanele ihlolwe ngokomongo wayo futhi bafinyelele imigomo ethize. Okwamanje, ake sibheke le ethandwa kakhulu. Imijikelezo ezahlukene preconditions futhi postconditions? Nangu wazi uyisicekelo:
ngenkathi «isimo» ukwenza «ikhodi»
Jikelele theory nohlaka umjikelezo postcondition
Le ndlela ikhodi phasi uma umjikelezo opharetha ne postcondition ukuqaliswa izindleko zomzimba. Uma uthi nhlá ukuthi kungase kuzwakale kuyindida: ngempela, kungani ubeke izimo ngemva ekukhishweni ikhodi? Kodwa lutho kuyinto exakayo khona: isici yaleli fomu wukuthi ikhodi uyabulawa kungakhathaliseki izimo zabo ziyafezwa noma cha enza. Kodwa isikhathi 1 kuphela. Khona-ke izolandela isivivinyo, kungakhathaliseki konke, njengoba kufanele kube, noma cha. Futhi ngenxa yokuntuleka kwezinhlelo ezibanzi izimo zomzimba ezanele lomjikelezo zizozitshwa. Lesi isici esibalulekile kakhulu futhi ewusizo, okuyinto has a umjikelezo postcondition. On the isibonelo salokho Kwabikwa futhi lapho ungabona ukusebenza nokusebenzisa ngesineke lapha? Nasi isibonelo lomjikelezo nge postcondition:
uphinda
"Ikhodi"
kuze «Imibandela»
Jikelele theory umjikelezo isisekelo nge umbandela
Kodwa kuyinto inketho ethandwa kakhulu ncamashi lokhu. engavamile yayo itholakala iqiniso ukuthi kubulawa isimo ezidingekayo, ngaphandle le khodi akakaze ababulawa. Ngokuvamile, Ikhodi kakhulu esikalini futhi isebenze ukukhinyabezeka kwayo Imininingwane omubi kukhompyutha ukusebenza. Ngakho-ke, wasebenzisa ngempela uhlelo ngobuqili: iningi izingcezu ikhodi ibekwe ku izihibe noma amakilasi ngabanye ukuthi isikhalazo kuza nje noma yini ngesikhathi esifanele. Zonke lonke isikhathi le khodi, kodwa musa ukusebenzisa ikhomphyutha. Leli cebo ikuvumela ukuba ugcine kucutshungulwa amandla ukusayinda hlelo noma ezinye izinhlelo.
ukusebenza nokusebenzisa ngezilimi ezahlukene zokuhlela
A amazwi ambalwa mayelana ukusebenza okungokoqobo kwezimiso imijikelezo. Kufanele kuqashelwe lokuqala zonke konga isikhathi, kokubili umsebenzisi kanye uMklami. On the yesibili okuye kwashiwo, kungani, kungani kufanele amagama ambalwa ukusho mayelana ikhasimende. Iqiniso ukuthi waqhekeka waba izingxenye ehlukile evumela isofthiwe ukulayisha ngokushesha futhi ukusebenzisa, futhi ngokufanelekile, umsebenzisi ngeke kuphela siyojabula ukusebenzisa isofthiwe okunjalo. Ngaphezu kwalokho, le ndlela lapho ikhodi egcinwe emjikelezweni noma esihlukile (okuyinto okuvame ukubangelwa emzimbeni), futhi ivumela ukusebenza kahle ukusebenza. Kufanele ulethe irekhodi ijubane kule ngabanye inkumbulo amaseli. Ngakho, uma konke kwakudingeka wenziwe ngesandla, kwakuyodingeka ube ukuthola ngamunye futhi kukhona i entry ezifanele. A iluphu ivumela izikhathi eziningana noma ngisho inqwaba ukwehlisa isidingo ukwenza yonke into ngokwakho. Futhi ususa isici womuntu, okungaholela amahora kudingeka afune ikhodi eziyinkinga.
isiphetho
Ngakho, efingqa konke ebhaliwe, singasho ukuthi umjikelezo nge postcondition noma i kwenza ngendlela efanelekile yokulondoloza imali ngaphandle izinga imihlatshelo. Futhi uma ubhala izinhlelo eziyinkimbinkimbi, kuba omunye okungcono uMklami abangane, amsize ukuba wenze ikhodi kulula ukuba afeze futhi ukufunda. Ngakho-ke, lapho ebhalela ikhodi kwabo akuvumelani bangafuni ukusebenzisa umjikelezo nge postcondition noma umbandela - basuke eziklanyelwe ngokuqondile lula inqubo ukudalwa isofthiwe, futhi izosebenza ngokumelene naye - hhayi ukuthatha leli thuba.