文件输入输出代码

 1 #include<iomanip>
 2 #include<fstream>
 3 #include<iostream>
 4 #include<string>
 5 using namespace std;
 6 int main()
 7 {
 8     struct Student
 9     {
10     char name[10];
11     long id;
12     char major[10];
13     float score;
14     float score1;
15     };
16 
17     Student a,b,c;
18     Student d,e,f;
19 
20     ofstream outstr("E:\a.txt",ios::out);
21     ifstream instr;
22 if(!outstr)
23     {
24     cout<<"Error!"<<endl;
25 return -1;
26     }
27 cout<<"请输入学生姓名，学号，专业，成绩，成绩："<<endl;
28 
29 cin>>a.name>>a.id>>a.major>>a.score>>a.score1;
30 cin>>b.name>>b.id>>b.major>>b.score>>b.score1;
31 cin>>c.name>>c.id>>c.major>>c.score>>c.score1;
32 
33 outstr<<setw(6)<<a.name<<setw(6)<<a.id<<setw(6)<<a.major<<setw(6)<<a.score<<setw(6)<<a.score1<<endl;
34 outstr<<setw(6)<<b.name<<setw(6)<<b.id<<setw(6)<<b.major<<setw(6)<<b.score<<setw(6)<<b.score1<<endl;
35 outstr<<setw(6)<<c.name<<setw(6)<<c.id<<setw(6)<<c.major<<setw(6)<<c.score<<setw(6)<<c.score1<<endl;
36 
37 outstr.close();
38 
39 instr.open("E:\a.txt");
40 
41 instr>>d.name>>d.id>>d.major>>d.score>>d.score1;
42 instr>>e.name>>e.id>>e.major>>e.score>>e.score1;
43 instr>>f.name>>f.id>>f.major>>f.score>>f.score1;
44 
45 cout<<d.name<<d.id<<d.major<<d.score<<d.score1<<endl;
46 cout<<e.name<<e.id<<e.major<<e.score<<e.score1<<endl;
47 cout<<f.name<<f.id<<f.major<<f.score<<f.score1<<endl;
48 
49 instr.close();
50 system("pause");
51 return 0;
52 }