阅读以下说明和C++程序代码,将应填入一丛皿一处的字句写在答题纸的对应栏内。
【说明】
在下面的C++代码中,类SalesTicket能够完成打印票据正文的功能,类HeadDecorator与FootDecorator分别完成打印票据的台头和脚注的功能。己知该程序运行后的输出结果如下所示,请填补该程序代码中的空缺。
这是票据的台头!
这是票据正文!
这是票据的脚注!
---------------------
这是票据的台头!
这是票据的脚注!
【C++程序代码】
#include<iostream>
using namespace std;
class SalesTicket{
public:
(1) printTicket(){cout <<”这是票据正文!” << endl;}
};
class Decorator : public SalesTicket{
SalesTicket *ticket;
public:
Decorator(SalesTicket *t){ticket = t;}
void printTicket ( ){
if(ticket! = NULL)
ticket->printTicket ( ) ;
}
};
class HeadDecorator : public Decorator{
public:
HeadDecorator(SalesTicket *t) : (2) {}
void printTicket(){
cout << “这是票据的台头!” << endl;
Decorator :: printTicket();
}
};
class FootDecorator:public Decorator{
public:
FootDecorator(SalesTicket *t) : (3) {}
void printTicket(){
Decorator::printTicket():
cout << “这是票据的脚注!” << endl;
}
};
void main (void){
SalesTicket t;
FootDecorator f(&t):
HeadDecorator h( (4) ):
h. printTicket():
cout << “------------------------------” << endl;
FootDecorator a(NULL);
HeadDecorator b( (5) );
b .printTicket();
}