常见英文面试笔试题目VIP免费

C/C++ProgramminginterviewquestionsandanswersBySatishShetty,July14th,2004Whatisencapsulation??Containingandhidinginformationaboutanobject,suchasinternaldatastructuresandcode.Encapsulationisolatestheinternalcomplexityofanobject'soperationfromtherestoftheapplication.Forexample,aclientcomponentaskingfornetrevenuefromabusinessobjectneednotknowthedata'sorigin.Whatisinheritance?Inheritanceallowsoneclasstoreusethestateandbehaviorofanotherclass.Thederivedclassinheritsthepropertiesandmethodimplementationsofthebaseclassandextendsitbyoverridingmethodsandaddingadditionalpropertiesandmethods.WhatisPolymorphism??Polymorphismallowsaclienttotreatdifferentobjectsinthesamewayeveniftheywerecreatedfromdifferentclassesandexhibitdifferentbehaviors.YoucanuseimplementationinheritancetoachievepolymorphisminlanguagessuchasC++andJava.Baseclassobject'spointercaninvokemethodsinderivedclassobjects.YoucanalsoachievepolymorphisminC++byfunctionoverloadingandoperatoroverloading.Whatisconstructororctor?Constructorcreatesanobjectandinitializesit.Italsocreatesvtableforvirtualfunctions.Itisdifferentfromothermethodsinaclass.Whatisdestructor?Destructorusuallydeletesanyextraresourcesallocatedbytheobject.Whatisdefaultconstructor?Constructorwithnoargumentsoralltheargumentshasdefaultvalues.Whatiscopyconstructor?Constructorwhichinitializestheit'sobjectmembervariables(byshallowcopying)withanotherobjectofthesameclass.Ifyoudon'timplementoneinyourclassthencompilerimplementsoneforyou.forexample:BooObj1(10);//callingBooconstructorBooObj2(Obj1);//callingboocopyconstructorBooObj2=Obj1;//callingboocopyconstructorWhenarecopyconstructorscalled?Copyconstructorsarecalledinfollowingcases:a)whenafunctionreturnsanobjectofthatclassbyvalueb)whentheobjectofthatclassispassedbyvalueasanargumenttoafunctionc)whenyouconstructanobjectbasedonanotherobjectofthesameclassd)WhencompilergeneratesatemporaryobjectWhatisassignmentoperator?Defaultassignmentoperatorhandlesassigningoneobjecttoanotherofthesameclass.Membertomembercopy(shallowcopy)Whatarealltheimplicitmemberfunctionsoftheclass?Orwhatareallthefunctionswhichcompilerimplementsforusifwedon'tdefineone.??defaultctorcopyctorassignmentoperatordefaultdestructoraddressoperatorWhatisconversionconstructor?constructorwithasingleargumentmakesthatconstructorasconversionctoranditcanbeusedfortypeconversion.forexample:classBoo{public:Boo(inti);};BooBooObject=10;//assigningint10BooobjectWhatisconversionoperator??classcanhaveapublicmethodforspecificdatatypeconversions.forexample:classBoo{doublevalue;public:Boo(inti)operatordouble(){returnvalue;}};BooBooObject;doublei=BooObject;//assigningobjecttovariableioftypedouble.nowconversionoperatorgetscalledtoassignthevalue.Whatisdiffbetweenmalloc()/free()andnew/delete?mallocallocatesmemoryforobjectinheapbutdoesn'tinvokeobject'sconstructortoinitiallizetheobject.newallocatesmemoryandalsoinvokesconstructortoinitializetheobject.malloc()andfree()donotsupportobjectsemanticsDoesnotconstructanddestructobjectsstring*ptr=(string*)(malloc(sizeof(string)))ArenotsafeDoesnotcalculatethesizeoftheobjectsthatitconstructReturnsapointertovoidint*p=(int*)(malloc(sizeof(int)));int*p=newint;Arenotextensiblenewanddeletecanbeoverloadedinaclass"delete"firstcallstheobject'sterminationroutine(i.e.itsdestructor)andthenreleasesthespacetheobjectoccupiedontheheapmemory.Ifanarrayofobjectswascreate...