第15周【项目1-用二进制文件处理学生成绩】

#include <iostream>
#include <fstream>
#include <cstring>
#include <cstdlib>

using namespace std;

class Student
{
public:
Student(){};
Student(int n, string nam, double c, double m, double e);
void set_value(int n,string nam, double c, double m, double e);
double get_cpp()
{
return cpp;
}
double get_math()
{
return math;
}
double get_english()
{
return english;
}
double get_total()
{
return total;
}
void set_cpp(double c)
{
cpp=c;
}
void set_math(double m)
{
math=m;
}
void set_english(double e)
{
english=e;
}
void set_total(double t)
{
total=t;
}
friend ostream& operator<<(ostream &,Student &s);
private:
int num;
string name;
double cpp;
double math;
double english;
double total;
};
Student::Student(int n, string nam, double c, double m, double e):num(n),name(nam),cpp(c),math(m),english(e)
{
total=c+m+e;
}
void Student::set_value(int n,string nam, double c, double m, double e)
{
num=n;
name=nam;
cpp=c;
math=m;
english=e;
total=c+m+e;
}
ostream& operator<<(ostream &out,Student &s)
{
out<<s.num<<" "<<s.name<<" "<<s.cpp<<" "<<s.math<<" "<<s.english<<" "<<s.total<<endl;
return out;
}
int main()
{
Student stud[100];
int i,n;
string sname;
double scpp, smath, senglish;
//（二）读入学生的成绩，并求出总分，用对象数组进行存储。
ifstream infile("score.dat",ios::in);
if(!infile)
{
cerr<<"open error!"<<endl;
exit(1);
}
for(i=0;i<100;i++)
{
infile>>n>>sname>>scpp>>smath>>senglish;
stud[i].set_value(n,sname,scpp,smath,senglish);
}
infile.close();
//（三）将所有数据保存到一个二进制文件binary_score.dat中
ofstream outfile("binary_score.dat",ios::out|ios::binary);
if(!outfile)
{
cerr<<"open error!"<<endl;
exit(1);
}
for(i=0;i<100;++i)
{
outfile.write((char*)&stud[i],sizeof(stud[i]));
}
//（三）最后在文件中写入你自己的各科成绩
cin>>n>>sname>>scpp>>smath>>senglish;
Student me(n,sname,scpp,smath,senglish);
outfile.write((char*)&me,sizeof(me));
outfile.close();
//（四）为验证输出文件正确，再将binary_score.dat中的记录逐一读出到学生对象中并输出查看。
Student s;
ifstream infile2("binary_score.dat",ios::in|ios::binary);
if(!infile2)
{
cerr<<"open error!"<<endl;
exit(1);
}
while(true)
{
infile2.read((char*)&s, sizeof(s));
if(infile2.eof()) break;
cout<<s;
}
infile2.close();
return 0;
}