C++ 结构，文件无法编译，向量数组有问题

Question

我不明白哪里出了问题，但似乎问题出在向量上，但在网上搜索后无法解决这个问题。

编译器的错误如下所示：

main.cpp:25:21: error: expected primary-expression before ‘&’ token
   25 |     getdata(student &s,file);
      |                     ^
main.cpp:26:23: error: expected primary-expression before ‘&’ token
   26 |     printdata(student &s,file);
      |                       ^
main.cpp: In function ‘void getdata(student&, std::fstream)’:
main.cpp:36:15: error: no match for ‘operator[]’ (operand types are ‘student’ and ‘int’)
   36 |         cin>>s[i].name;
      |               ^
main.cpp:38:15: error: no match for ‘operator[]’ (operand types are ‘student’ and ‘int’)
   38 |         cin>>s[i].sno;
      |               ^
main.cpp:40:15: error: no match for ‘operator[]’ (operand types are ‘student’ and ‘int’)
   40 |         cin>>s[i].mark;
      |               ^
main.cpp:44:34: error: no match for ‘operator[]’ (operand types are ‘student’ and ‘int’)
   44 |         file<<"Student name: "<<s[i].name<<endl;
      |                                  ^
main.cpp:45:36: error: no match for ‘operator[]’ (operand types are ‘student’ and ‘int’)
   45 |         file<<"Student number: "<<s[i].snum<<endl;
      |                                    ^
main.cpp:46:33: error: no match for ‘operator[]’ (operand types are ‘student’ and ‘int’)
   46 |         file<<"term mark:   "<<s[i].mark<<endl;
      |                                 ^

#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

struct student
{
    string name;
    int snum;
    double mark;
};

void getdata(student &s,fstream file);
void printdata(student &s,fstream file);

int main ()
{
    fstream file;
    int number;
    vector <student> s(3);

    cout<<"Enter number of students to account for: "<<endl;
    cin>>number;
    
    getdata(student &s,file);
    printdata(student &s,file);

}

void getdata(student &s, fstream file)
{
    file.open("Students.txt",ios::out);
    for(int i=0; i<3; i++)
    {
        cout<<"Enter your name: "<<endl;
        cin>>s[i].name;
        cout<<"Enter your student number: "<<endl;
        cin>>s[i].sno;
        cout<<"Enter your term mark: "<<endl;
        cin>>s[i].mark;
        cout<<endl;
        
        file<<"----------------------"<<endl;
        file<<"Student name: "<<s[i].name<<endl;
        file<<"Student number: "<<s[i].snum<<endl;
        file<<"term mark:   "<<s[i].mark<<endl;
        file<<"----------------------"<<endl;
        
    }
    file.close();
}

void printdata(student &s, fstream file)
{
    file.open("Students.txt",ios::in);
    string read;
    while(getline(cin,read))
    {
        cout<<read<<endl;
    }
    file.close();
}

Answer 1

这些不是有效的函数调用：

getdata(student &s,file);
printdata(student &s,file);

它们应该是：

getdata(s,file);
printdata(s,file);

这会导致其他错误，因为您的函数显然需要 vector<student>，但只需要 student。

您也不能按值传递 fstream 对象。它们必须是参考文献。

将您的函数参数列表更改为如下所示：

void getdata(vector<student> &s, fstream &file);
void printdata(vector<student> &s, fstream &file);

成员 .sno 也有错别字，您的意思是 .snum

解决所有这些问题，你的程序就会编译，然后你至少可以开始调试它，看看它是否能正常工作。

C++ 结构，文件无法编译，向量数组有问题

C++ Structures, file does not compile, vector array has issues

c++

compiler-errors

function

vector

data-structures