第三講類和對象 2doublereal,Complex(inti) cout<<"IntConstructorcalled"<<endl;real=i;imag=0;real=r;imag= intmainComplexc1(7,8);Complexc2=c1 3}cout<<c1.real<<""<<3}析構(gòu)函數(shù)析構(gòu)函數(shù)面加4classprivatechar*p;CString()p=new}~CString()CString::~{delete[]}5classCtest{~Ctest(){cout<<"destructorcalled"<<endl;intmain()Ctestcout<<"EndMain"<<endl;return0;}

EndMain6析構(gòu)函數(shù)和運算符deletepTest=newpTest=new Test=newCtestdelete[]7~CMyclass(){cout~CMyclass(){cout<<"destructor"<<endl;returnsobj; }intreturnsobj; }intobj=fun(obj);//函數(shù)調(diào)用的返回值（臨時對象）被return0; }

9classDemointid;Demo(int{id=printf("id=%d,Construct\n",}{printf("id=%d,Destruct\n",}voidstaticvoidstaticDemoDemod33printf("fun\n");}intmainDemod4printf("main\n");Demod5 rintf"endmain\n");return0;} #include<iostream>using CMyclass(){};CMyclass(CMyclass&c)coutcout<<"copyconstructor"<<}~CMyclass(){cout<<"destructor"<<endl;}CMclassccout<<"test"}CMclassccout<<"test"<<}copy intcopydestructor//返回值臨時對象消亡 //局部變量消亡 //全局變量消亡}class Vs.

intw,h;staticintCRectangle(intw_,intstaticvoid

可以通過：

CRectangle*p=&r; .CRectangle&refintn=上面這三種方式效果和類名::成員名沒區(qū)別靜態(tài)成員變量不classCMyclass{intn;staticintsizeof(CMyclass class{staticintnTotalArea;staticintnTotalArea;CRectanleintw_,intstaticvoid{w=w_;h=h_;nTotalNumber++;nTotalArea+=w*h;{nTotalNumber--;nTotalArea-=w*h;}voidcoutcout<<nTotalNumber<<","<<nTotalArea<<}intCRectanle::nTotalArea=0 int{CRectangler1(3,3),}void{cout<<w<<","<<nTotalNumber<<","<<nTotalArea<<endl;//wrongCRectangler;CRectangler;class{staticintnTotalArea;staticintnTotalArea;CRectangle(intw_,intstaticvoidCRectangle nTotalNumbernTotalArea的值 構(gòu)造函CRectangle::CRectangle(CRectangle&r){w=r.w; h=r.h;nTotalNumber++;nTotalArea+=w*h;}??

構(gòu)造函數(shù)(調(diào)用方式Complexc1,c2(2),Complex*pc1=newComplex;ComplexComplex*pc1=newComplex;Complex*pc2=newComplex(3,4)；Testarray1[3]={1,Test(1,2)Test*pArray[3]={newTest(4),newTest(1,2)構(gòu)造函數(shù) Complex Complexc2= 析構(gòu)函數(shù)(定義~類名(){析造函數(shù)(調(diào)用時機(jī)全局變量函數(shù)中靜態(tài)變量函數(shù)中靜態(tài)變量函數(shù)參數(shù)函數(shù)中變量函數(shù)返回值全局變量函數(shù)中靜態(tài)變量 函數(shù)中靜態(tài)變量C++的標(biāo)準(zhǔn)int#include<iostream>usingintA(intx_):x(x_)cout<<x<<"constructorcalled"<<}~A(){cout<<x<<"destructorcalled"<<endl;intmain()}2constructor2constructor2destructorclassA intintA(intx_):x(x_)cout<<x<<"constructorcalled"<<}

Aa=f();return0;}A(constA&a//本例中dev需要此const其他編譯器不要x=2+a.x;cout<<"copycalled"<<}

~A(){cout<<x<<"destructorcalled"<<endl;AAf(return

1constructorcalledcopycalled12destructor12destructor12destructor10destructor intmain()intA(intx_):x(x_)cout<<x<<"constructorcalled"<<

Aa=f();return0;}A(constA&a){x=2+a.x;cout<<"copycalled"<<

}~A(){cout<<x<<"destructorcalled"<<endl;Af(Areturn}

1constructor10destructor

conststringSCHOOL_NAME=“Pekingintn,constint*p=&*p=5;//編譯出錯n=4; p=&m;constconstint*p1;int*p2;1= 2;//okp2=p1;p2=(int*)p1; voidMyPrintf(constchar*p{ this//編譯出錯cout<<p;//ok}intintconstint&r=n;r=5;//errorn=4;前面加const關(guān)鍵字classSample}constSampleObj; (靜態(tài)成員函數(shù)除外)public:intvoidpublic:intvoidGetValue()voidfunc(){}intvalue=0;}intconstSample//VisualStudio2010//VisualStudio2010中沒有問題，在DevC++中，要為Sample類編寫無 classSamplevoidGetValue()voidGetValue()voidSample::GetValue()const cout<<}constT&voidPrintfObj(constSample&o{ o.GetValue();//okSample&r=(Sample&)o;//必須強(qiáng)制類型轉(zhuǎn)換 }int

CTest(){n=1;intmain()intGetValue()const{returnnintmain()CTestobjTest2;objTest2.GetValue();}

","輸出結(jié)果:1,

intintintCTyre(intr,intw:radiusr,width{classCCar{//汽車類intprice;//價格CTyretyre;CCar(intp,inttr,inttw{}}int{CCarcar;//compile{),{…}函數(shù)/變量 表達(dá)式中的函數(shù),變量有定 classCTyre{CTyre(){cout<<"CTyrecontructor"<<endl;~CTyre(){cout<<"CTyredestructor"<<endl;CEngine(){cout<<CEngine(){cout<<"CEnginecontructor"<<endl;~CEngine(){cout<<"CEnginedestructor"<<endl;classCCar{CTyretyre;CCar(){cout<<"CCarcontructor"<<endl;~CCar(){cout<<"CCardestructor"<<endl;CCarcar;return0;}intCCarcar;return0;}CEnginecontructorCTyrecontructorCCarcontructorCCardestructorCTyredestructorCEnginedestructor →它里面包 對，也會A(){cout<<“default”<<endl;}A(A&a){cout<<"copy"<<endl;}

classB{Aa;};intmain(){Bb1,

而調(diào) } 初始化const成員 intclassCDemoconstintconstintnum//

int& int cout<<sizeof(CDemo)cout<<sizeof(CDemo)<<endl;return0;//輸出結(jié)果是友元 classCCar;//提 classintfriendintMostExpensiveCarCCarcars[],inttotal); friendvoidCDriver::ModifyCar(CCar* }inttmpMax=-for(inti=0;i<total;++i}int}int{}classB 一類的成員函數(shù)(classBvoidclassAfriendvoidclassclassintfriendclass CCarvoidModifyCar(){// intint return thisclassCCar{int

structintprice=p;voidSetPrice(CCar*this,int}}intmain(){CCarc