C/C++函数参数传递机制详解及实例

/*
*测试函数参数传递机制
*/
class CRect {

public:
  int height;
  int widht;

  CRect() {
    height = 0;
    widht = 0;
  }

  CRect(int height, int widht) {
    this->height = height;
    this->widht = widht;
  }

};

//（1）传址调用（传指针）
int RectAreaPoint(CRect *rect) {
  int result = rect->height * rect->widht;
  rect->height = 20;
  return result;
}

//（2）引用传递
int RectAreaRefer(CRect &rect) {
  int result = rect.height * rect.widht;
  rect.height = 30;
  return result;

}

//（3）传值调用
int RectArea(CRect rect) {
  int result = rect.height * rect.widht;
  rect.height = 40;
  return result;
}

//测试代码逻辑
void testPoint() {
  CRect rect(10, 10);
  cout << "面积：" << RectAreaPoint(&rect) << endl;
  cout << "面积：" << RectAreaRefer(rect) << endl;
  cout << "rect.height：" << rect.height << endl;
  cout << "面积：" << RectArea(rect) << endl;
  cout << "rect.height：" << rect.height << endl;
}

//测试结果
面积：100
面积：200
rect.height：30
面积：300
rect.height：30