虚函数“形状”赋值

我似乎无法让我的气缸类正确执行其打印和音量功能 . 以下是赋值的说明：设计一个名为Shape的类，它是一个抽象基类 . Shape有两个纯虚函数，printShapeName和print .

Shape包含另外两个虚函数，area和volume，每个函数都有一个返回零值的默认实现 .

Point类从Shape继承这些实现（点的面积和体积均为零） . Point具有x和y坐标私有成员 .

Class Circle派生自具有公共继承的Point . 圆的体积为0.0，因此不会覆盖基类成员函数体积 . 圆形具有非零区域，因此在此类中覆盖区域功能 . 写入get和set函数以返回并为Circle指定新的半径 .

Class Cylinder派生自Circle并具有公共继承 . A Cylinder的面积和体积与Circle的面积和体积不同，因此该类别中的面积和体积函数都被覆盖 . 写入get和set函数以返回高度并指定新的高度 .

创建一个点，一个圆和一个圆柱然后打印结果 .

//
//  Shape.hpp
//  HW6_VirtualFunctions
//
//  Created by Aviv Fedida on 11/25/17.
//  Copyright © 2017 Aviv Fedida. All rights reserved.
//

#ifndef Shape_hpp
#define Shape_hpp

#include <stdio.h>
#include <iostream>
#include <cmath>
using namespace std;

class Shape {
protected:  // protected members
    double width, height, radius, pi, x, y;
public:
    void setWidth(double a);    // prototype for width setter
    void setHeight(double b);   // prototype for height setter
    void setX(double c);
    void setY(double d);
    void setRad(double r);
    void setPi(double p);
    double getWidth() { // get width to return only
        return width;
    }
    double getHeight() { // get height to return only
        return height;
    }
    double getX() {
        return x;
    }
    double getY() {
        return y;
    }
    double getRad() {
        return radius;
    }
    double getPi() {
        return pi;
    }
    // Create public virtual functions
    virtual void printShapeName() = 0; // pure virtual for printing shape's name
    virtual void print(double a, double b) = 0; // pure virtual print function
    virtual double area() {  // virtual area function returns default null
        return 0;
    }
    virtual double volume() {  // virtual default volume function returns null
        return 0;
    }
};  // END BASE CLASS -------------------------------------------------------------------------------------

class Point: public Shape {
    // x & y coordinates needed for a point
public:
    // Prototypes for print & set functions
    void printShapeName();
    void print(double a, double b);
    };  // end first derived class ------------------------------------------------------------------------

class Circle: public Point {
public:
    //  Protoypes for print functions
    void printShapeName();
    void print(double r, double p);
    //  Prototypes for area & volume functions
    double area(double r, double p);
};  // end second derived class ----------------------------------------------------------------------------

class Cylinder: public Circle {
public:
    double area(double r, double p);
    void printShapeName();
    double volume(double r, double p, double h);
    void print(double r, double p, double h);
}; // end third and final derived class --------------------------------------------------------------------------

//  Some definitions outside classes
//--------------------------------------------------    BEGIN   -----------------------------------------------------------
//  Shape base class setter functions defined
void Shape::setWidth(double a) {
    width = a;
}
void Shape::setHeight(double b) {
    height = b;
}
void Shape::setX(double c) {
    x = c;
}
void Shape::setY(double d) {
    y = d;
}
void Shape::setRad(double r) {
    radius = r;
}
void Shape::setPi(double p) {
    p = 3.1416;
    pi = p;
}

void Point::printShapeName() {   // Print name of class
    cout << "Point " << endl;
}
void Point::print(double a, double b) {   // Print values within class
    cout << "(" << a << "," << b << ")" << endl;
}

void Circle::printShapeName() {
    cout << "Circle " << endl;
}
//  Circle area function defined
double Circle::area(double r, double p) {
    double area;
    area = p*(pow(r,2));
    return area;
}
void Circle::print(double r, double p) {
    cout << "Area of circle is: " << area(r, p) << endl;
    cout << "Volume of circle is: " << volume() << endl;
}

void Cylinder::printShapeName() {
    cout << "Cylinder " << endl;
}
double Cylinder::area(double r, double p) {
    double area;
    area = 2*p*r;
    return area;
}
double Cylinder::volume(double r, double p, double h) {
    double volume;
    volume = p*(pow(r,2))*h;
    return volume;
}
void Cylinder::print(double r, double p, double h) {
    cout << "Area of cylinder is: " << area(r, p) << endl;
    cout << "Volume of cylinder is: " << volume(r, p, h) << endl;
}



#endif /* Shape_hpp */

//
//  main.cpp

#include <iostream>
#include "Shape.hpp"
#include "Shape.cpp"

using namespace std;

int main() {
    double pi = 3.1416; // Variable for pi
    //  Instantiate class objects
    Point guard;
    Circle k;
    Cylinder cid;
    //  Instantiate pointers to class objects
    Shape *pptr;
    Shape *kptr;
    Shape *cptr;
    //  Assign memory of objects to pointer variables
    pptr = &guard;
    kptr = &k;
    cptr = &cid;
    //  Call objects via pointers and print members
    pptr->printShapeName();
    pptr->print(5,6);
    cout << '\n';
    kptr->printShapeName();
    kptr->print(9,pi);
    cout << '\n';
    cptr->printShapeName();
    cptr->getHeight();
    cptr->setHeight(8);
    cptr->print(5,pi);
    return 0;
}

如果我尝试在Cylinder类的print函数中添加第三个height参数，则会出错 . 它最终使用我的Circle类定义 .