问答题

[说明]
以下代码实现了对象引用作为函数参数，仔细阅读以下代码，分析运行结果，填入 (n) 处。
[代码]
#include＜iostream.h＞
class Sample
int x,y;
public:
Sample() x=y=0;
Sample (int i, int j ) x=i; y＝j;
void copy ( Sample &s ).,
void setxy ( int i, int j ) x＝i; y＝j;
void print ( cout＜＜"x="＜＜x＜＜end1 ; cout ＜＜"y="＜＜y＜＜end1;
;
void Sample: copy ( Sample &s )
X=S.X;
y=s.y;
void func ( Sample s1, Sample &s2 )
s1.setxy ( 10,20 );
s2.setxy ( 30,40 );
void main ( )
Sample p ( 1,2 ) ,q;
q.copy ( p );
time ( p,q );
p.print ( );
q.print ( );
运行结果
(1)
(2)
(3)
(4)