c++ - 表面积/体积

Question

我正在尝试让这段代码计算盒子的表面积和体积。它编译但不输出正确的数据。我认为问题可能出在 void Box::零件内，但碰壁了。或者它可能是 Height = Height 但我无法以任何其他方式让它运行而不会出错。

代码如下:

#include <iostream>
#include "Box.hpp"

using namespace std;


int main()
{
    Box box;
    double boxHeight, boxWidth, boxLength;

    cout << "This program will tell you the surface area and volume of a box" << endl;
    cout << "Please enter the height " << endl;
    cin >> boxHeight;
    cout << "Please enter the width " << endl;
    cin >> boxWidth;
    cout << "Please enter the length" << endl;
    cin >> boxLength;

    box.setHeight();

    cout << "The surface area is " << box.getSurfaceArea() << endl;
    cout << "The volume is " << box.getVolume() << endl;


    return 0;
}

void Box::setHeight(){
    if(Height< 0)
        cout << "Error.  Must enter a positive number " << endl;
    else
        Height = Height;
    }


void Box::setLength(){
   if(Length< 0)
        cout << "Error.  Must enter a positive number " << endl;
    else
        Length = Length;
    }


void Box::setWidth(){
   if(Width< 0)
        cout << "Error.  Must enter a positive number " << endl;
    else
        Width = Width;
    }


double Box::getSurfaceArea(){

    return 2*(Length*Width) + 2*(Length*Height) + 2*(Width + Height);
}



double Box::getVolume(){

    return Length*Width*Height;
}

hpp 文件是这样的:

#ifndef BOX_HPP_INCLUDED
#define BOX_HPP_INCLUDED

class Box
{
public:
    void setHeight();
    void setWidth();
    void setLength();
    double getVolume();
    double getSurfaceArea();

private:
    double Length;
    double Width;
    double Height;
};


#endif 

Answer 1

首先，您需要在您的 setter 中传递您想要设置的值:

void setHeight(double height);
void setWidth(double width);
void setLength(double length);

void Box::setHeight(double height)
{
    if(height < 0)
        cout << "Error.  Must enter a positive number " << endl;
    else
        Height = height;
}

void Box::setWidth(double width)
{
    if(width < 0)
        cout << "Error.  Must enter a positive number " << endl;
    else
        Width = width;
}

void Box::setLength(double length)
{
    if(length < 0)
        cout << "Error.  Must enter a positive number " << endl;
    else
        Length = length;
}

此外，您不仅需要设置框的高度，还需要设置框的宽度和长度:

box.setHeight(boxHeight);
box.setWidth(boxWidth);
box.setLength(boxLength);

这应该可以解决问题。