实验九多态性与虚函数.docVIP

实验九 多态性与虚函数 一、实验要求 1.领悟面向对象编程技术的多态性特征。 2.熟练掌握虚函数的设计和使用。 二、实验内容 1. 定义一个类A，有两个add成员函数，参数是数字类型，就为加法；参数是字符类型，就为字符转化为字符串，并实现连接，请用程序实现。 2. 有一个汽车类vehicle，将它作为基类派生类小车类car、卡车类truck和轮船类boat，定义这些类并定义一个虚函数用来显示各类信息。 三、实验小结 #include iostream using namespace std; class vehicle { public: virtual void pr() {coutthis is a vehicleendl;} }; class Car:public vehicle { public: void pr() {coutthis is a carendl;} }; class truck:public vehicle { public: void pr() {coutthis is a truckendl;} }; class boat:public vehicle { public: void pr() {coutthis is a boatendl;} }; void main() { vehicle *p1 = new Car; p1-pr(); vehicle *p2 = new truck; p2-pr(); vehicle *p3 = new boat; p3-pr(); vehicle *p4 = new vehicle; p4-pr(); delete p1; delete p2; delete p3; delete p4; } #includeiostream using namespace std; class Vehicle { public: virtual void pr()=0; protected: char Name[20]; }; class Car:public Vehicle { public: Car(char *name) { strcpy(Name,name); } void pr() {coutNameendl;} }; class Truck:public Vehicle { public: Truck(char *name) { strcpy(Name,name); } void pr() {coutNameendl;} }; class Boat:public Vehicle { public: Boat(char *name) { strcpy(Name,name); } void pr() {coutNameendl;} }; void main() { Vehicle *vp; Car car(奔驰); Truck truck(运输卡车); Boat boat(游艇); vp=car; vp-pr (); vp=truck; vp-pr (); vp=boat; vp-pr (); }