Overloaded ostream operator error in c++ - c++

Question

I try to overload ostream operator in a class Student as follows:
//Student.h
class Student
{
public:
Student(){}
~Student(){}
friend std::ostream& operator<< (std::ostream&,const Student&);
friend std::istream& operator>> (std::istream&,const Student&);
private:
char* snum;
};
//Student.cpp
#include "Student.h"
std::ostream& operator<< (std::ostream& output,const Student& c)
{
output<<c.snum<<", "<<c.name<<", "<<c.email<<endl;
return output;
}
std::istream& operator>> (std::istream& input,const Student& cN)
{
cout<<"Input number: ";
input>>cN.snum;
return input;
}
//main.cpp
#include "Student.h"
int main()
{
Student st;
std::cin >> st;
std::cout << st << std::endl;
return 0;
}
But when i input the snum,i get error message "Segmentation Fault".
I change char* snum; to char snum;,it return compiler error The operation "std::istream>> const char" is illegal.
Thank you for help.

Answer 1

You need that snum will point on allocate memory and then you can input it with data, for exemple:
char* p_var = new char[20]; // 20 bytes allocation
// ... using p_var
delete[] p_var; // Releasep_var memory
In your case, you should do the allocation in the Ctor and the release in the Dtor.
you can read this for more info:
http://www.cplusplus.com/doc/tutorial/basic_io/

Answer 2

tell me if your problem got solved by using below changes...
class Student
{
private:
char snum;
char name;
char email;
public:
Student(){};
~Student(){};
friend std::ostream& operator<< (std::ostream&,Student&);
friend std::istream& operator>> (std::istream&,Student&);
};
std::ostream& operator<< (std::ostream& output,Student& c)
{
output<<c.snum<<", "<<c.name<<", "<<c.email<<endl;
return output;
}
std::istream& operator>> (std::istream& input, Student& cN)
{
cout<<"Input number: ";
input>>cN.snum;
input>>cN.name;
input>>cN.email;
return input;
}
int main()
{
Student st;
std::cin >> st;
std::cout << st << std::endl;
return 0;
}
use string or char array or assign char *x some memory before using for cin...