有关圆类的包含，不懂circle::circle(circle &s):p(s.p)中p（s.p）的含义

[w26hu]

见下

#include<iostream.h>
#include<iomanip.h>
const float PI=3.14159;	
class point	
{
public:	
	point(int a=0, int b=0);	
	point(point &p);	
    ~point();
    void display(void);
	void move(int xx,int yy);
private:	
	int x;
	int y;
};

point::point(int a,int b)
{
  x=a;
  y=b;
  cout<<"point<<endl;
}
point::~point()
{
  cout<<"point<<endl;
}
point::point(point &p)
{
  x=p.x;
  y=p.y;
  cout<<"point"<<endl;
}
void point::display(void)
{
  cout<<"x="<<x<<" y="<<y<<endl;
}
void point::move(int xx,int yy)
{
  x+=xx;
  y+=yy;
}
class circle	
{
 public:	
    circle(int a=0,int b=0,float c=1);	
    circle(circle &s);	
	~circle();
	void display(void);
	float get_cum();	
    float get_area();	
 private:	
    point p;   
	float r;
};

circle::circle(int a,int b,float c):p(a,b)
{ 
  if(c<=0)
   r=1;
  else 
   r=c;
  cout<<"circle<<endl;
}	
circle::circle(circle &s):p(s.p)
{
  r=s.r; 
  cout<<"circle"<<endl;
}
circle::~circle()
{
  cout<<"circle<<endl;
}
void circle::display(void)
{
  p.display();
  cout<<"r="<<r<<endl;
}
float circle::get_cum()	
{
  return (2*PI*r);
}
float circle::get_area()
{
  return (PI*r*r);
}

int main ()
{
 int a,b;
 float c;
 cout<<"; 
 cin>>a>>b;
 cout<<
 cin>>c;
 circle t(a,b,c);  	
 t.display(); 
 cout"<<setw(6)<<setprecision(3)<<t.get_cum()
	 <<setw(6)<<setprecision(3)<<t.get_area()<<endl;
 return(0);
} 

[sniffer12345]

你可以把： circle::circle(circle &s):p(s.p) { r=s.r; cout<<"circle"<<endl; } 改成 circle::circle(circle &s) { p = s.p; r=s.r; cout<<"circle"<<endl; } 试试，然后观察cout<<"point"<<endl;这一句输出的内容

[buyong]

吧p变量初始化为s.p

[漂浮一生]

要多调试啊，你在主函数中声明两个circle类的对象，用一个circle对象初始化另一circle对象时， 会调用circle的拷贝构造函数circle(circle &s)，但又发现里面有另一个类的对象， 那么会去调用另一个point类的拷贝构造函数point(point &p);

[wu4357815]

circle::circle(circle &s):p(s.p) //这其实就是一个复制构造函数，其实p(s.p)就是类的组合。简单点说就是
                                                       //把调用p的复制构造函数，把s中p的复制一下。
{
  r=s.r; 
  cout<<"circle"<<endl;
}