类C ++结构 [英] C++ Struct on Class

问题描述

需要一些指南

我有一个代码

  struct Point 
 {
 int x; 
 int y; 
}; 
  

那么在我的班上我有一个函数

  class MyClass 
 {
 private：
 Point myPoint [4]; 
 public：
 void setPoint（）; 
}; 
 
 void MyClass :: setPoint（）
 {
 int xData，yData; 
 
 for（int i = 0; i <4; i ++）
 {
 cout<< 请输入x-ordinate：; 
 cin>> xData; 
 
 cout<< 请输入y-ordinate：; 
 cin>> yData; 
 
 //在这部分代码引发分段核心转储。 
 myPoint [i] .x = xData; 
 myPoint [i] .y = yData; 
} 
 
} 
  

在第二循环，分段核心转储发生。

  > #includeMyClass.h
 
 int main（）
 {
 MyClass * mClass; 
 
 mclass-> setPoint（）; 
} 
  

感谢您的帮助。

解决方案

您必须在使用前分配内存指针：

  int main b $ b {
 MyClass * mClass = new MyClass（）; 
 mclass-> setPoint（）; 
 return 0; 
} 
  

need some guide here

I got a code which is

struct Point
{
   int x;
   int y;
};

then at my class i got a function

class MyClass
{
   private:
      Point myPoint[4];
   public:
     void setPoint();
};

void MyClass::setPoint()
{
   int xData,yData;

   for (int i=0;i<4;i++)
   {
      cout << "Please enter x-ordinate:";
      cin >> xData;

      cout << "Please enter y-ordinate:";
      cin >> yData;

      //at this part the code throw a segmentation core dump.
      myPoint[i].x = xData;
      myPoint[i].y = yData;
   }

}

On first run nothing happen, but on 2nd loop, segmentation core dump occur. whats wrong with my code?

Additional code on main.cpp

#include "MyClass.h"

int main()
{
MyClass *mClass;

mclass->setPoint();
}

Thanks for helping.

解决方案

You must allocate memory before use pointer:

int main()
{
    MyClass *mClass = new MyClass ();
    mclass->setPoint();
    return 0;
}

这篇关于类C ++结构的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！