C++动态分配数组的方式让我不知所措

所以我要在一个文本文件中读取一个作业，该文件包含四条关于一个人的信息，这些信息用逗号分隔。我正在尝试读取名为"lab8.txt"的文件，分解信息，然后允许用户查看信息以及修改信息。目前，我专注于从文本文件中获取信息，并能够向用户显示这些信息。我在整个代码中有几个错误，希望有人能帮我纠正这些错误，并告诉我我做错了什么。感谢您的任何帮助。文本文件如下所示。很抱歉，我知道这是一个很大的问题，但作业是由我的教授以外的人创建的，我所在的班级比做这项作业的教授班落后得多。

M123456789，Smith，Joe，1978年12月30日，M2345689，Jones，Marc，1980年1月28日，M000022，巴赫，约翰，1685/03/31，M000024，莫扎特，沃尔夫冈，1791/01/27，M000023，Handel，George，1759/04/14，M222222，Geisel，Theodor，1904/03/02，M000044，Sousa，Philip，1854/11/06，M000046，The Frog，Kermit，1955/05/09，M000049，小猪，小姐，1974/10/13，M000049，M000043，Henson，James，1936/09/24，

我的代码包括三个部分。我所有函数定义的主函数、头文件和cpp文件。我将按顺序列出它们。

//主要功能

#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include <cstdlib>
#include <classname.h>

using namespace std;
int main()
{
    File var1;
    var1.MenuEditor();
}
#ifndef CLASSNAME_H_INCLUDED
#define CLASSNAME_H_INCLUDED
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;
struct StudentData
{
    string StudentId;
    string LastName;
    string FirstName;
    string BirthDate;
};

//头文件

class File
{
    public:
        File();
        File(string);
        bool ReadRecordsFromFile(string);
        void MenuEditor();
        void SearchFile (string);
    private:
        int number_records;
        void BreakUp (string);
        void SortName (StudentData, string);
        StudentData allocate(string);
        void AddRecord(string);
        void DeleteRecord(string);
        void ModifyRecord(string);
        bool ReadRecordsFromFile(string fileName);
        void WriteRecordsToFile(string fileName);
};
#endif // CLASSNAME_H_INCLUDED

//带有函数定义的CPP文件

#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include <cstdlib>
#include "classname.h"
using namespace std;
// This method returns a true if you can open the file or a false if you can
// not
// You will need to add calls to your methods to allocate the array and
// "breakup" the input string.
File::File(string fileName)
{
}
bool File::ReadRecordsFromFile(string fileName)
{
    string input_line;
    ifstream infile(fileName.c_str()); // This might be useful for you.
    if(!infile)
    {
        return false;
    }
    Records=new StudentData[100];
// number_of_records or some other variable to store current record count
    number_of_records = 0;
    while(getline(infile, input_line))
    {
// CHECK to see if you need to allocate or expand dynamic array here
//  - Use method defined in class to do the allocation
// Call Method to break up data stored in input_line
// and than store new data into dynamic array
//  - See Files++ code sample on blackboard
        string temp,MNum,
        int Current_comma= input_line.find(",");
        Records[number_of_records].StudentID = input_line.substr(0, Current_comma);
        temp= input_line.substr(Current_comma+1);
        cout << [number_of_records].StudentID <<endl;
        number_of_records = number_of_records + 1;
    }
    return true;
}
// This method returns a true if you can open the file for writing and
// false if not
bool Lab8::WriteRecordsToFile(string fileName)
{
    string output_line;
    ofstream outfile(fileName.c_str());
    if(!outfile)
    {
        return false;
    }
// number_of_records or some other variable to store current record count class
    for (int rec_count = 0; rec_count < number_of_records; rec_count++)
    {
// CREATE a seperate output line out of your data or create it inline
        fileobject << output_line << endl;
        number_of_records = number_of_records + 1;
    }
    outfile.close();
    return true;
}


File::StudentData allocate(string);
{
}

void File::AddRecord(string fileName)
{
}
void File::DeleteRecord(string fileName)
{
}
void File::ModifyRecord(string fileName)
{
}
void File::SortName(string fileName)
{
}
void File::SearchFile(string fileName)
{
}
void File::MenuEditor()
{
    ReadRecordsFromFile("lab8.txt")
    cout << "Press 1 to add file." <<endl;
    cout << "Press 2 to delete file." <<endl;
    cout << "Press 3 to modify file." <<endl;
    cout << "Press 4 to sort file." <<endl;
    cout << "Press 5 to search file." <<endl ;
    getline(cin,  int menuchoice);
    if (menuchoice == 1)
    {
        AddRecord();
    }
    else if(menuchoice == 2)
    {
        DeleteRecord();
    }
    else if(menuchoice == 3)
    {
        ModifyRecord();
    }
    else if(menuchoice == 4)
    {
        SearchFile();
    }
    else if(menuchoice == 5)
    {
        SortName();
    }
    else
    {
        cout << "You done messed up. Re run the program" << endl;
    }
}