C++ primer 学习笔记 2 快速入门2

练习 1.20
#include< iostream >
#include"Sales_item.h"
usingnamespace std;
int main()
{
Sales_item item;
cout << "请输入销售记录:" << endl;
while ( cin >> item )
{
cout << "售出册数，总销售额和平均价:" << item << endl;
}
return 0;

}
练习 1.21
#include< iostream >
#include"Sales_item.h"
usingnamespace std;
int main()
{
Sales_item item1;
Sales_item item2;
cout << "请输入两个ISBN相同的销售记录:" << endl;
cin >> item1>> item2;
if (compareIsbn(item1, item2))
cout << "汇总信息：ISBN、售出本数、销售额和平均售价为 "
<< item1+ item2 << endl;
else
cout << "两条销售记录的ISBN不同" << endl;
return 0;
}

练习 1.22

#include< iostream >
#include"Sales_item.h"
usingnamespace std;

int main()
{
Sales_item total,trans;
cout << "请输入几条销售记录："<< endl;
if (cin >> total)
{
while (cin >> trans)
{
if (compareIsbn(total, trans))
total =total+ trans;
else
{
cout<< "ISBN
不同" << endl;
return -1;
}

}
cout << "汇总信息：ISBN、售出本数、销售额和平均售价为"
<< total<< endl;
}
else
{
cout << "没有数据" << endl;
return -1;
}
return 0;

}

练习1.23

#include< iostream >
#include"Sales_item.h"
usingnamespace std;
int main()
{
Sales_itemtrans1,trans2;
int num = 1;
cout << "请输入销售记录：" << endl;
if (cin >> trans1)
{
while (cin >> trans2)
{
if(compareIsbn(trans1, trans2))
num++;
else
{
cout<< trans1.isbn() << "共有"
<< num<< "条销售记录" <<endl;
trans1 =trans2;
num = 1;
}
}
cout <<trans1.isbn() << "共有"
<< num<< "条销售记录" <<endl;
}
else
{
cerr << "没有数据" << endl;
return -1;
}
return 0;
}