const char *初值赋值以及文件读取

#include<iostream>
#include<fstream>
#include<string>
#include<cstring>
using namespace std;
class Student
{
public:
    Student(string number="", double score=, const char *name="noname")
    {
        this->number = number;
        this->score = score;
        this->name = new char[strlen(name) + ];//之前写的程序总是忘记开辟空间这一步
        strcpy(this->name, name);
    }
    ~Student() {
        //cout<<"~Stu()...."<<endl;
        delete[] name;
    }
        friend istream &operator>>(istream & is, Student& dt) {
        is >> dt.number>>dt.name>>dt.score;
        return is;
    }
    friend ostream &operator<<(ostream & os, Student& dt) {

        os << dt.name << "\t" << dt.number << "\t" << dt.score << "\n";
        return os;
    }
private:
    char *name;
    string number;
    double score;
};

int main()
{
    Student st[];
    int i;
    for(i=;i<;i++)
    cin>>st[i];
    ofstream fout("date.dat",ios::binary);  

    for(i=;i<;i++)
    fout.write((char*)&st[i],sizeof(st[i]));
    fout.close( );  

    ifstream fin("date.dat",ios::binary);
    for(i=;i<;i++)
    fin.read((char*)&st[i],sizeof(st[i]));
     cout <<"姓名\t"<<"学号\t"<<"分数\n";
    for(i=;i<;i++)
    cout <<st[i];
    fin.close( );
    getchar();getchar();

    return ;
}