對C 中類的組合的理解

#include

#include
using
namespace std;
class
point
//point類宣告
point
(point &p)
;int
getx()
intgety()
private
:int x,y;};
point::
point
(point &p)
class
line
//line類的宣告
private
:              
point p1,p2;
double len;};
//組合類的建構函式
line:: line (point xp1, point xp2):p1
(xp1),p2
(xp2)
//組合類的複製建構函式
line:: line (line &l):p1
(l.p1),p2
(l.p2)
//主函式
intmain()
{ point myp1(1
,1),
myp2(4
,5);
//建立point類的物件
line line
(myp1,myp2)
;//建立line類的物件
line line2
(line)
;//利用拷貝建構函式建立乙個新物件
cout<<
"the length of the line is:"
;  cout

"the length of the line2 is:"
;  cout
<