c++ - 从作为指针的类成员获取值

Question

给定以下代码:

#include <iostream>
using namespace std;

class CRectangle {

  public:
    int *width, *height;
    CRectangle (int,int);
    ~CRectangle ();
    int area () {return (*width * *height);}
};

CRectangle::CRectangle (int a, int b) {
  width = new int;
  height = new int;
  *width = a;
  *height = b;
}

CRectangle::~CRectangle () {
  delete width;
  delete height;
}

int main () {
  CRectangle rect (3,4), rectb (5,6);
  cout << "rect area: " << rect.area() << endl;
  cout << "rectb area: " << rectb.area() << endl;

  CRectangle * p = new CRectangle(10,10);

  cout << "rect area: " << p->*height << endl;

  return 0;
}

如何让最后的 cout 语句生效？

Answer 1

移动解引用运算符。 p->height 指的是整型指针height。然后将 * 放在前面取消引用 int 指针。

cout << "rect area: " << *p->height << endl;