实验六 继承与派生.pptx

继承与组合一、实验目的了解继承在面向对象程序设计中的重要作用。进一步理解继承与派生的概念。掌握通过继承派生出一个新的类的方法。了解虚基类的作用和用法。掌握类的组合二、实验内容1．请先阅读下面的程序，写出程序运行的结果，然后再上机运行程序，验证自己分析的结 果是否正确。(1)#include iostream using namespace std; class A{public:A(){coutA::A() called.\n;}virtual ~A(){coutA::~A() called.\n;}};class B:public A{public:B(int i)coutB::B() called.\n; buf=new char[i];{}virtual ~B(){ delete []buf; coutB::~B() called.\n;}private:char *buf;};void fun(A *a){ coutMay you succeed!endl; delete a;}int main(){A *a=new B(15); fun(a);return 0;}1、（1）程序运行结果：A::A() called.B::B() called. May you succeed! B::~B() called.A::~A() called.(2)#includeiostream using namespace std; class A{public:A(int a,int b):x(a),y(b){ coutA constructor...endl; } void Add(int a,int b){ x+=a;y+=b;}void display(){ cout(x,y);}~A(){coutdestructor A...endl;} private:int x,y;};class B:private A{ private:int i,j; A Aobj;public:B(int a,int b,int c,int d):A(a,b),i(c),j(d) ,Aobj(1,1){ coutB constructor...endl;}void Add(int x1,int y1,int x2,int y2){A::Add(x1,y1);i+=x2; j+=y2;}void display(){A::display(); Aobj.display();cout(i,j)endl;}~B(){coutdestructor B...endl;}};int main(){B b(1,2,3,4);b.display(); b.Add(1,3,5,7);b.display(); return 0;}（2）程序运行结果：A constructor... A constructor... B constructor... (1,2) (1,1) (3,4)(2,5) (1,1) (8,11)destructor B... destructor A... destructor A...(3)#includeiostream using namespace std; class A{public:A(int a):x(a){ coutA constructor...xendl; } int f(){return ++x;}~A(){coutdestructor A...endl;} private:int x;};class B:public virtual A{ private:int y;A Aobj; public:B(int a,int b,int c):A(a),y(c),Aobj(c){ coutB constructor...yendl;} int f(){A::f();Aobj.f(); return ++y;}void display(){ coutA::f()\tAobj.f()\tf()endl; }~B(){coutdestructor B...endl;}};class C:public B{ public:C(int a,int b,int c):B(a,b,c),A(0){ coutC constructor...endl;}};class D:public C,public virtual A{ public:D(int a,int b,int c):C(a,b,c),A(c){ coutD constructor...endl;}~D(){coutdestructor D...endl;}};int main(){D d(7,8,9);d.f();d.