实验题目（1）:
定义一个抽象类容器类，其中定义了若干纯虚函数，实现求表面积、体积、输出等功能。由此抽象类派生出正方体、球体和圆柱体等多个派生类，根据需要定义自己的成员变量，在各个派生类中重新定义各纯虚函数，实现各自类中相应功能，各个类成员的初始化均由本类构造函数实现。
① 在主函数中，定义容器类的指针和各个派生类的对象，使指针指向不同对象处调用相同的函数能执行不同的函数代码，从而实现动态多态性。
② 定义一个顶层函数void TopPrint(Container &r);使得主函数中调用该函数时，根据实在参数所有的类自动调用对应类的输出函数。
③ 主函数中定义一个Container类对象，观察编译时的错误信息，从而得出什么结论？
#include<iostream>
using namespace std;
class Container
{
protected:
double radius;
public:
Container(double r)
{
radius = r;
}
Container()
{
radius = 0;
}
virtual double area() = 0; //求表面积
virtual double volume() = 0; //求体积
virtual void print() = 0; //输出相关信息
};
class Cube:public Container //正方体
{
private:
double length;
public:
Cube(double x)
{
length = x;
}
virtual double area() //求表面积
{
return 6 * length * length;
}
virtual double volume() //求体积
{
return length * length * length;
}
virtual void print() //输出相关信息
{
cout << "正方体表面积为：" << area() << " 正方体体积为：" << volume() << endl;
}
};
class Sphere:public Container //球体
{
private:
int radius;
public:
Sphere(int r)
{
radius = r;
}
virtual double area() //求表面积
{
return 4 * 3.141592 * radius * radius;
}
virtual double volume() //求体积
{
return (3.141592 * (4.0 / 3) * radius * radius * radius);
}
virtual void print() //输出相关信息
{
cout << "球体表面积为：" << area() << " 球体体积为：" << volume() << endl;
}
};
class Cylinder :public Container //圆柱体
{
private:
double height;
double radius;
public:
Cylinder(double r, double h)
{
radius = r;
height = h;
}
virtual double area() //求表面积
{
return 2 * 3.141592 * radius *( radius+ height);
}
virtual double volume() //求体积
{
return 3.141592 * height * radius * radius;
}
virtual void print() //输出相关信息
{
cout << "圆柱体表面积为：" << area() << " 圆柱体体积为："<< volume() << endl;
}
};
int main()
{
Container *p;
Cube cu(1); //正方体
Sphere sp(1); //球体
Cylinder cy(2,3); //圆柱体
p = &cu;
cout << p->area() << endl;
cout << p->volume() << endl;
p->print();
p = &sp;
cout << p->area() << endl;
cout << p->volume() << endl;
p->print();
p = &cy;
cout << p->area() << endl;
cout << p->volume() << endl;
p->print();
getchar();
return 0;
}
或者
#include<iostream>
using namespace std;
class Container
{
protected:
double radius;
public:
Container(double r)
{
radius = r;
}
Container()
{
radius = 0;
}
virtual double area() = 0; //求表面积
virtual double volume() = 0; //求体积
virtual void print() = 0; //输出相关信息
};
class Cube :public Container //正方体
{
private:
double length;
public:
Cube(double x)
{
length = x;
}
double area() //求表面积
{
return 6 * length * length;
}
double volume() //求体积
{
return length * length * length;
}
void print() //输出相关信息
{
cout << "正方体表面积为：" << area() << " 正方体体积为：" << volume() << endl;
}
};
class Sphere :public Container //球体
{
public:
Sphere(int r) :Container(r)
{
;
}
double area() //求表面积
{
return 4 * 3.141592 * radius * radius;
}
double volume() //求体积
{
return (3.141592 * (4.0 / 3) * radius * radius * radius);
}
void print() //输出相关信息
{
cout << "球体表面积为：" << area() << " 球体体积为：" << volume() << endl;
}
};
class Cylinder :public Container //圆柱体
{
private:
double height;
public:
Cylinder(double r, double h) :Container(r)
{
height = h;
}
double area() //求表面积
{
return 2 * 3.141592 * radius *(radius + height);
}
double volume() //求体积
{
return 3.141592 * height * radius * radius;
}
void print() //输出相关信息
{
cout << "圆柱体表面积为：" << area() << " 圆柱体体积为：" << volume() << endl;
}
};
int main()
{
Container *p;
Cube cu(1); //正方体
Sphere sp(1); //球体
Cylinder cy(2, 3); //圆柱体
p = &cu;
cout << p->area() << endl;
cout << p->volume() << endl;
p->print();
p = &sp;
cout << p->area() << endl;
cout << p->volume() << endl;
p->print();
p = &cy;
cout << p->area() << endl;
cout << p->volume() << endl;
p->print();
getchar();
return 0;
}
实验题目2：
定义复数类Complex，有实部、虚部两个私有成员变量，在该类中定义多个重载的构造函数、定义析构函数和输出函数print，复数的输出形如12-3i，在类中重载+、−、*、/、++（分前++和后++）。在主函数（直接用实验教材P210代码）中定义复数类的对象，实现复数的各种算术运算，通过重载实现静态多态性。
#include<iostream>
using namespace std;
class Complex
{
private:
float real;
float imag;
public:
Complex(float r = 0, float i = 0)
{
real = r;
imag = i;
}
void print()
{
cout << real;
if (imag != 0)
{
if (imag > 0)
{
cout << " + ";
}
cout << imag << " i";
}
cout << endl;
}
friend Complex operator +(const Complex &a, const Complex &b);
friend Complex operator -(const Complex &a, const Complex &b);
friend Complex operator *(const Complex &a, const Complex &b);
friend Complex operator /(const Complex &a, const Complex &b);
friend Complex operator ++ ( Complex &a);
Complex operator ++(int);
};
Complex operator +(const Complex &a,const Complex &b)
{
Complex temp;
temp.real = a.real + b.real;
temp.imag = a.imag + b.imag;
return temp;
}
Complex operator -(const Complex &a, const Complex &b)
{
Complex temp;
temp.real = a.real - b.real;
temp.imag = a.imag - b.imag;
return temp;
}
Complex operator *(const Complex &a, const Complex &b)
{
Complex temp;
temp.real = a.real * b.real;
temp.imag = a.imag * b.imag;
return temp;
}
Complex operator /(const Complex &a, const Complex &b)
{
Complex temp;
temp.real = a.real / b.real;
temp.imag = a.imag / b.imag;
return temp;
}
Complex operator ++ (Complex &a)
{
++a.real;
++a.imag;
return a;
}
Complex Complex::operator ++(int)
{
real++;
imag++;
return *this;
}
int main()
{
//Complex A1(2.3f, 4.6f), A2(3.6f, 2.8f);
Complex A1(12, 14), A2(8, 17);
Complex A3, A4, A5, A6;
A3 = A1 + A2;
A4 = A1 - A2;
A5 = A1 * A2;
A6 = A1 / A2;
cout << "A1 = ";
A1.print();
cout << endl << "A2 = ";
A2.print();
cout << endl << "A3 = A1 + A2 = ";
A3.print();
cout << endl << "A4 = A1 - A2 = ";
A4.print();
cout << endl << "A5 = A1 * A2 = ";
A5.print();
cout << endl << "A6 = A1 / A2 = ";
A6.print();
A3 = ++A1;
cout << endl << "after A3 = ++A1 , ";
cout << "A1= ";
A1.print();
cout << endl << "A3 =";
A3.print();
A4 = A2++;
cout << endl << "after A4 = A2++ , ";
cout << "A2= ";
A2.print();
cout << endl << "A4= ";
A4.print();
getchar();
return 0;
}
用成员函数重载双目运算符*和/：
Complex operator *( Complex a);
Complex operator /( Complex a);
friend Complex operator ++ ( Complex &a);
Complex operator ++(int);
Complex Complex::operator *( Complex a)
{
real = real * a.real;
imag = imag * a.imag;
return *this;
}
Complex Complex::operator /( Complex a)
{
Complex temp;
real = real / a.real;
imag = imag / a.imag;
return *this;
}
Complex operator ++ (Complex &a)
{
++a.real;
++a.imag;
return a;
}
Complex Complex::operator ++(int)
{
real++;
imag++;
return *this;
}