c++ - 将字符串元素添加到动态数组

Question

解析文件并需要使用数组将学生添加到结构 vector 中，该数组包含特定于该类(class)行的学生姓名。

在我的 course.h 文件中:

struct Course {
    std::string name;
    int enrollment;
    int maxEnrollment;

    std::string* students; ///< array of student names

    Course(std::string courseName, int maxEnrollmentPermitted);

    bool enroll(std::string studentName);

    void print(std::ostream& output);
};

在我的 course.cpp 文件中:

bool Course::enroll(std::string studentName) {
    this->students = new std::string[studentName];
    if (this->enrollment < this->maxEnrollment) {
        this->enrollment++;
        return true;
    }
    else {
        return false;

在我的源文件中:

void processEnrollmentRequests(istream& enrollmentRequestsFile, vector<Course>& courses) {
    // Read the requests, one at a time, serving each one
    string courseName;
    enrollmentRequestsFile >> courseName;

    while (enrollmentRequestsFile) {
        enrollmentRequestsFile >> ws;
        string studentName;
        getline(enrollmentRequestsFile, studentName);

        int pos = search(courses, courseName);
        if (pos >= 0) {
            // Found a matching course
            bool enrolled = courses[pos].enroll(studentName);
            if (enrolled) {
                cout << studentName << " has enrolled in " << courseName << endl;
            }
            else {
                // course is full
                cout << studentName << " cannot enroll in " << courseName << endl;
            }
        }
        else {
            // course does not exist
            cout << studentName << " cannot enroll in " << courseName << endl;
        }
        enrollmentRequestsFile >> courseName;
    }
}
        }
    }

我似乎无法使用 this->students = new std::string[studentName] 将收集到的学生姓名添加到数组中。收到一条错误消息，提示 must have integral or enumeration type。

Answer 1

new SomeThing[size] 用于声明数组。使用字符串作为大小没有意义。

假设 students 的大小限制为 maxEnrollment，您可以使用:

if (this->enrollment < this->maxEnrollment) {
    this->students[this->enrollment++] = studentName;
    return true;
}
else {
    return false;