




版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請進行舉報或認領
文檔簡介
Project3OverwritetheMemberAdministrationSystemwiththePHPFrameworkLaravelTask1IntroductiontoObject-OrientedProgrammingSchoolofSoftware,ChengduPolytechnicLecturer:MuQichunIntroductiontoObject-OrientedProgrammingTheso-called"ProcedureOriented"or"PO"referstothatinordertoaccomplishonething,weneedtodivideitintoseveralstepsandperformtheminsequence.Inprogramming,itmeanstodividetheprojectrequirementsintoindividualmethodsandindividualdata,executetheminspecificordertofinallygetthetaskdone.Theso-called"ObjectOriented"or"OO"meansthatbeforewecouldcompleteatask,wecouldabstractconceptsofobjectfromthematter,addsomeattributesandmethodstotheobjectsandfinallyleteachobjectexecutetheirownmethods.Wehavefinishedtwoprojectsbefore.Weappliedtheprocedure-orientedprogrammingmethodologytowritetheprograms.Aswearewritingaprogram,thereisanothertypicalmethodologywecanapply,whichisobject-orientedprogramming.IntroductiontoObject-OrientedProgrammingLet'strytounderstandthetwodifferentprogrammingmethodologiesthroughanexample.Forinstance,ifwewanttodothelaundryusingawashingmachine,incaseofprocedure-orientedmethodology,wecangetitdoneinfollowingway:Putinclothes(method)>>>Pourinlaundrydetergent(method)>>>Addwater(method)>>>Wash(method)>>>Dry(method)Butifweapplytheobject-orientedmethodology,wecouldgetthelaundrydoneasfollows:First,abstracttwoobjects,"human"and"washingmachine."Next,addattributesandmethodstoobject"human",including"puttinginclothes"(method),"pouringinlaundrydetergent"(method)and"addingwater"(method).Addattributesandmethodstoobject"washingmachine",including"washing"(method)and"drying"(method).IntroductiontoObject-OrientedProgrammingNowwiththeobjects,attributesandmethods,wecaninvokerelevantcontentsandgetthetaskdone.Next,invokeinturn:Human.Puttinginclothes(method)>>>Human.Pouringinlaundrydetergent(method)>>>Human.Addingwater(method)>>>WashingMachine.Washing(method)>>>WashingMachine.Drying(method).IntroductiontoObject-OrientedProgrammingWecouldseethatwecanfavorablyfinishthetaskinbothways.Butwhatadvantagesanddisadvantagesdothetwomethodologiespossessrespectively?1Procedure-orientedprogrammingAdvantagesHighefficiency;intelligible;comprisedofenforceable,separatesteps;succinct.DisadvantagesHighdegreeofcoupling;poorextensibility;difficulttomaintain.2Object-orientedprogrammingAdvantagesLowdegreeofcoupling,easytobeusedrepeatedly;highextensibility;maintanence-friendly.Inaddition,object-orientedprogrammingalsohascharacteristicssuchasencapsulation,inheritanceandpolymorphismwhichenablingdesigningofsystemswithlowdegreeofcoupling,thusmakingthemmoreflexibleandeasiertomaintain.DisadvantagesLowerefficientcomparedwithprocedure-orientedprogramming.IntroductiontoObject-OrientedProgrammingGenerally,wecanapplytheprocedure-orientedprogrammingmethodologyforsomesimpleprojects.Butifwearedesigningcomplex,large-scalesystem,itissuggestedthatobject-orientedprogrammingmethodologyshouldbeapplied.ThreeCharacteristicsofObject-OrientedProgramming:EncapsulationNextlet'stakealookthethreecharacteristicsofobject-orientedprogramming:EncapsulationInheritancePolymorphism1EncapsulationTheso-calledencapsulationmeanstoencapsulateanobjectivematterinanabstractiveclass,andthenencapsulateitsattributesandmethods,definingthemonlyavailablewithintheclass.Andadditionalauthorizationwouldberequiredifexternalclassesormethodstrytoaccessattributesandmethodsencapsulatedwithinaclass.PHPprovidesthreeaccessmodifiers.Public:represents"global"and"shared",accessiblewithin,outsideaclassandinasubclass.Protected:represents"underprotection",onlyaccessibleinitsclassandthesubclass.Private:represents"private",accessibleonlywithinitsclass,neitheroutsidetheclassnorinthesubclass.Nextlet'slookatanexampleshowingtheencapsulationcharacteristicofobject-orientedmethodology.ThreeCharacteristicsofObject-OrientedProgramming:EncapsulationByrunningaboveprogram,wecannowunderstandtheencapsulationcharacteristicofobject-orientedprogramming.ThreeCharacteristicsofObject-OrientedProgramming:Inheritance2InheritanceTheso-calledinheritancereferstothatanewclassisallowedtobeproducedbyinheritingsomeorallofthecharacteristicsofanoriginalclass.Theoriginalclassiscalledparentclass,andthenewclassiscalledsubclass.Thesubclasscannotonlydirectlyinheritcommoncharacteristicsfromtheparentclass,butalsocreateitsownspecialcharacteristics.Wecantrytounderstandtheinheritancecharacteristicofobject-orientedprogrammingbyfollowingexample.ThreeCharacteristicsofObject-OrientedProgramming:Polymorphism3PolymorphismTheso-calledpolymorphismreferstothatanobjectcanoccurindifferentformsindifferentsituations(instantiated).Inotherwords,amethodinaparentclasscanbeoverwrittenandrewritteninitssubclasstofulfillotherdifferentrequirements.Theinstancebelowwillexplainthepolymorphismcharacteristicofobject-orientedprogramming.Wecouldseethatthereisamethodas"run"intheparentclass"bus."Thesubclass"car"hasinheritedfrom"bus",andthemethod"run"intheparentclassisoverwrittenandrewrittenini
溫馨提示
- 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請下載最新的WinRAR軟件解壓。
- 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
- 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會有圖紙預覽,若沒有圖紙預覽就沒有圖紙。
- 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
- 5. 人人文庫網(wǎng)僅提供信息存儲空間,僅對用戶上傳內(nèi)容的表現(xiàn)方式做保護處理,對用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對任何下載內(nèi)容負責。
- 6. 下載文件中如有侵權(quán)或不適當內(nèi)容,請與我們聯(lián)系,我們立即糾正。
- 7. 本站不保證下載資源的準確性、安全性和完整性, 同時也不承擔用戶因使用這些下載資源對自己和他人造成任何形式的傷害或損失。
最新文檔
- 公司游艇團建活動方案
- 高等教育評估師資格考試的相關(guān)試題及答案
- 2025年虛擬現(xiàn)實技術(shù)工程師考試試卷及答案
- 2025年現(xiàn)代農(nóng)業(yè)技術(shù)推廣考試試卷及答案
- 2025年心理咨詢師職業(yè)資格考試試卷及答案
- 2025年食品安全管理體系考試試題及答案
- 2025年生物醫(yī)學工程技術(shù)考試卷及答案
- 2025年數(shù)據(jù)科學與大數(shù)據(jù)技術(shù)專業(yè)考試題及答案
- 2025年名師課堂與教學改革實踐能力考核試題及答案
- 2025年護理心理學考試題及答案
- 慢性硬膜下血腫護理要點大揭秘
- “微”力量微博營銷
- 2022-2023學年山東省菏澤市成武縣人教版四年級下冊期末考試數(shù)學試卷(解析版)
- 2023建筑業(yè)10項新技術(shù)
- 預防醫(yī)學英文版課件:Occupational hazards injury
- 無人船自主航行設計方案
- NBT10497-2021 水電工程水庫塌岸與滑坡治理技術(shù)規(guī)程
- 陜西省銅川市初中語文八年級期末高分試卷詳細答案和解析
- 《非物質(zhì)文化遺產(chǎn)數(shù)字化保護 數(shù)字資源采集和著錄 第9部分:傳統(tǒng)技藝》
- 小企業(yè)會計準則轉(zhuǎn)為企業(yè)會計準則實務操
- 江蘇省揚州市邗江區(qū)三校2023年高一數(shù)學第二學期期末質(zhì)量跟蹤監(jiān)視試題含解析
評論
0/150
提交評論