调用空函数问题

Calling void function problems

本文关键字:问题 函数 调用      更新时间:2023-10-16

您好,我在代码中调用 void initialize() 函数时遇到问题。我应该得到一个看起来像这样的数组

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其中数组在 Initialize() 中定义,变量来自 FIN 、SteamPipe 和 GridPT 类。我的代码在数组之前给了我第一组答案,但是当它到达数组时,我只得到符号"?",这是它在类 GridPT 中指定的。我认为我调用 void 函数的方式是错误的还是传递变量有问题?我已经尝试取出 const 但仍然是一样的。这是我的代码.h文件

#include<iostream>
#include<istream>
#include<cmath>
#include<cstdlib>
using namespace std;
const int maxFinHeight = 100;
const int maxFinWidth = 100;
class Steampipe
{
private:
  int height, width;
  double steamTemp;
public:
  Steampipe (int H = 0, int W = 0, double sT = 0.0)
  {
    height = H;
    width = W;
    steamTemp = sT;
  }
  // Access function definitions
  int getWidth()const{return width;};
  int getHeight()const{return height;};
  double getSteamTemp()const{return steamTemp;};
  void setWidth(int dummysteamwidth) {width = dummysteamwidth;};
  void setHeight(int dummysteamheight){height = dummysteamheight;};
  void setSteamTemp(double dummysteamtemp){steamTemp = dummysteamtemp;};
  // Access function definitions
  friend istream& operator>>(istream& , Steampipe& ); // YOU MUST DEFINE
  friend ostream& operator<<(ostream& , const Steampipe& ); // YOU MUST DEFINE
};
class GridPt
{
private:
  double temperature;
  char symbol;
public:
  GridPt(double t = 0.0, char s = '?')
  {
    temperature = t;
    symbol = s;
  }
  // Access function definitions
  double getTemperature()const {return temperature;};
  char getsymbol() const {return  symbol;};
  void setTemperature (double T=0) {T=temperature;}
  void setsymbol (char S='?'){S=symbol;}
};
class Fin
{
private:
  int width, height; //width and height of fin
  int pipeLocationX, pipeLocationY; //grid location of lower left corner of steampipe
  double boundaryTemp; //temperature of fin surroundings
  Steampipe Pipe; //steampipe object - COMPOSITION
  GridPt GridArray[maxFinHeight][maxFinWidth]; // array of GridPts - COMPOSITION
public:
  int getwidth() {return width;}
  int getheight() {return height;}
  int getpipeLocationX(){return pipeLocationX;}
  int getpipeLocationY(){return pipeLocationX;}
  double get_boundarytemp(){return boundaryTemp;}
  void setwidth (int w){w=width;}
  void setheight (int h){h=height;} 
  friend istream& operator>>(istream& , Fin& ); // YOU MUST DEFINE
  friend ostream& operator<<(ostream& , const Fin& ); // YOU MUST DEFINE
  void initialize(); // YOU MUST DEFINE
};
void Fin::initialize()
{
  int j(0) ,i(0);
  for ( i = 0; i < height; i++)
  {
    for (  j = 0; j < width; j++)
    {
      if (   j == pipeLocationX && i == pipeLocationY
          && i <  Pipe.getHeight() + pipeLocationY
          && j < Pipe.getWidth() + pipeLocationX)
      {
        GridArray [j][i].setTemperature(Pipe.getSteamTemp());
        GridArray [j][i].setsymbol('H');
      }
      else if (j == (width -1) || i == (height -1) || j == 0 || i == 0)
      {
        GridArray [j][i].setTemperature(boundaryTemp);
        GridArray [j][i].setsymbol('C');
      }
      else
      {
        GridArray [j][i].setTemperature((Pipe.getSteamTemp() + boundaryTemp)/2);
        GridArray [j][i].setsymbol('X');
      }
    }
  } 
}

istream &operator >> (istream & in, Fin& f)
{
  int   ws, hs; 
  double  ts;
  char comma;
  cout << "Enter the height of the fin (integer) >>> ";
  in >> f.height;
  cout << "Enter the width of the fin (integer) >>> " ;
  in >> f.width;
  cout << "Enter the height of the streampipe (integer) >>> ";
  in >>hs;
  f.Pipe.setHeight(hs);
  cout << "Enter the width of the steampipe (integer) >>> ";
  in >> ws;
  f.Pipe.setWidth(ws);
  cout << "Enter coordinates of lower left corner of steampipe (X,Y) >>> ";
  in >> f.pipeLocationX >> comma >> f.pipeLocationY;
  cout << "Enter the steam temperature (floating point) >>> ";
  in >> ts;
  f.Pipe.setSteamTemp(ts);
  cout << "Enter the temperature around the fin (floating point) >>> "; 
  in >> f.boundaryTemp;
  return in;
}
ostream &operator << (ostream &stream, const Fin& t)
{
  int i = 0;
  int j = 0;
  stream << "The width of the fin is " << t.width << endl;
  stream << "The height of the fin is " << t.height << endl;
  stream << "The outside temperature is " << t.boundaryTemp << endl;
  stream << "The lower left corner of the steam pipe is at " 
         << t.pipeLocationX <<      "," << t.pipeLocationY << endl;
  stream << "The steampipe width is " << t.Pipe.getWidth() << endl;
  stream << "the steampipe height is " << t.Pipe.getHeight() << endl;
  stream << "The temperature of the steam is " << t.Pipe.getSteamTemp() << endl;
  for ( i = 0; i < t.height; i++)
{
    for (  j = 0; j < t.width; j++)
    {
        if (j == t.pipeLocationX && i == t.pipeLocationY && i < t.Pipe.getHeight() + t.pipeLocationY && j < t.Pipe.getWidth() + t.pipeLocationX)
        {
            t.GridArray [j][i].getTemperature();
            stream<<t.GridArray [j][i].getsymbol();
        }
        else if (j == (t.width -1) || i == (t.height -1) || j == 0 || i == 0)
        {
            t.GridArray [j][i].getTemperature();
            stream<<t.GridArray [j][i].getsymbol();
        }
        else
        {
            t.GridArray [j][i].getTemperature();
            stream<<t.GridArray [j][i].getsymbol();
        }
    }stream<<endl;
}   
  int coorx(0),coory(0);char comma;
  stream << "Enter the coordinates of the gridpoint of interest (X,Y) >>> "
         << endl;
  cin>>coorx>>comma>>coory;
  stream<<"The temperature at location ("<<coorx<<","<<coory<<") is "
         << t.GridArray << endl;
  return stream;
}

我的驱动程序文件 cpp 是:

#include "pipe.h"
int main()
{
  Fin one; 
  cin >> one;
  one.initialize();
  cout << one;
  return 0;
}

任何建议将不胜感激。谢谢

在您的代码中,以下内容是错误的:

void setTemperature (double T=0) {T=temperature;}
void setsymbol (char S='?'){S=symbol;}

它必须是:

void setTemperature (double T=0) {temperature = T;}
void setsymbol (char S='?') { symbol = S;}

顺便说一句:将函数定义放在标头中不是一个好习惯(除非它是模板),而是将它们放在源文件中,标头中只有声明。

在代码中,您还可以直接在输出流中使用t.GridArray

stream<<t.GridArray; 这是行不通的。它不是一个函数,也不是一个流会理解的类型。使用已声明的 i 和 j 变量并单步执行数组的每个元素来打印它们,与初始化数组时相同。