c ++ csv逗号分隔文件条目，混合类型的麻烦答案

【问题标题】：c++ csv comma delimited file entries, trouble with mixed typesc ++ csv逗号分隔文件条目，混合类型的麻烦
【发布时间】：2021-02-10 17:38:36
【问题描述】：

测试文件

11111,Smith,Bob,10,9,8,10,9,10,92,89,90
11112,Doe,Jean,8,9,8,7,9,9,84,88,89
11113,Hardy,Joe,9,9,10,9,8,9,88,90,95

信息存储在

struct Student {
    std::string ID;
    std::string lName;
    std::string fName;
    int quiz1;
    int quiz2;
    int quiz3;
    int quiz4;
    int quiz5;
    int quiz6;
    int test1;
    int test2;
    int final;
    float total;
};

问题：添加成绩时，它只会正确读取一年级。我尝试了许多不同的方法，但这是迄今为止唯一一种甚至部分有效的方法:( 当手动设置学生结构时，测试值确实可以正常工作；所以读入的文件是问题

int main() {

    //add a place to store student info
    StudentGrades session;
    string inFile = "classGrades.txt";

    //open input file if possible or display an error message and exit with failure
    ifstream in;
    cout << "Opening File: " << inFile << "\n";
    in.open(inFile);
    if (in.is_open()) {
        cout << "File Open: " << inFile << "\n";
        string line;
        while (getline(in,line)) {
            //read in student info from file line by line to a Student object for each line
            Student student;
            std::stringstream stream(line); //record info from file
            getline(stream,student.ID,',');
            getline(stream,student.lName,',');
            getline(stream,student.fName,',');
            stream >> student.quiz1;
            stream >> student.quiz2;
            stream >> student.quiz3;
            stream >> student.quiz4;
            stream >> student.quiz5;
            stream >> student.quiz6;
            stream >> student.test1;
            stream >> student.test2;
            stream >> student.final;

            session.add(student);
       }
    }
    else
    {
        cout << "File could not be opened: " << inFile << "\n";
        exit(1);
    }
    //close the input file
    cout << "Closing File: " << inFile << "\n";
    in.close();
    cout << "File Closed: " << inFile << "\n";

    session.printStudentList(cout);

    return 0;
}

文件输出

Opening File: classGrades.txt
File Open: classGrades.txt
Closing File: classGrades.txt
File Closed: classGrades.txt
ID    | Last Name  | First Name  |    Q1 |    Q2 |    Q3 |    Q4 |    Q5 |    Q6 |    T1 |    T2 | Final | Total
11113 | Hardy      | Joe         |     9 |     0 |     0 |     0 |     0 |     0 |     0 |     0 |     0 |  2.25
11112 | Doe        | Jean        |     8 |     0 |     0 |     0 |     0 |     0 |     0 |     0 |     0 |     2
11111 | Smith      | Bob         |    10 |     0 |     0 |     0 |     0 |     0 |     0 |     0 |     0 |   2.5

【问题讨论】：

例如stream >> student.quiz2; 不会处理逗号。

标签： c++ csv struct delimiter ifstream

【解决方案1】：

您的问题是，与getline 不同，stream >> student.quiz1; 不会，因此当您尝试执行stream >> student.quiz2; 时，流中有,。您需要将该逗号从流中取出。你可以通过使用get 来“吃掉”角色，或者使用一个命名的char 来做到这一点

char eat_comma;

//...

stream >> student.quiz1 >> eat_comma;
stream >> student.quiz2 >> eat_comma;
stream >> student.quiz3 >> eat_comma;
stream >> student.quiz4 >> eat_comma;
stream >> student.quiz5 >> eat_comma;
stream >> student.quiz6 >> eat_comma;
stream >> student.test1 >> eat_comma;
stream >> student.test2 >> eat_comma;
stream >> student.final; // no comma after the last value

【讨论】：