Missing data inside the dat file after writing operation - missing-data

Question

I am trying to save the data the user inputted inside a linked-list and then store those data inside a file so that I can retrieve them back when I enter the 2nd option(as per in the int main()). Unfortunately, after I wrote the data into the file and check back the file, I found out that my data is missing and the file is filled with garbage.so I cant retrieve the data back. Is there any solution to this problem?? Thank you.
#include<iostream>
#include<cstdlib>
#include<iomanip>
#include<fstream>
using namespace std;
fstream fp;
class List{
private:
struct node{
string name;
string surname;
int idNum;
string nationality;
int number;
node *next;
}nod;
node* head;
node* curr;
node* temp;
public:
List();
bool isEmpty(node *head){
if(head==NULL){
return true;
}
else
return false;
}
void AddNode(string addName,string addsurName,int addId,string addNation,int addNumber);
void insertAsFirst(string addName,string addsurName,int addId,string addNation,int addNum);
//void DeleteNode(int delData);
void printList();
void write_linky(string name,string surName,int idNum,string nation,int number);
void read_linky();
}lb;
List::List(){
head=NULL;
curr=NULL;
temp=NULL;
}
void List::insertAsFirst(string addName,string addsurName,int addId, string addNation,int addNum){
node *n = new node;
n->name=addName;
n->surname=addsurName;
n->idNum=addId;
n->nationality=addNation;
n->number=addNum;
n->next = NULL;
head = n;
//last = temp;
}
void List::AddNode(string addName,string addsurName,int addId,string addNation,int addNum){
if(isEmpty(head)){
insertAsFirst(addName,addsurName,addId,addNation,addNum);
}
else{
node* n = new node;
n->next=NULL;
n->name=addName;
n->surname=addsurName;
n->idNum=addId;
n->nationality=addNation;
n->number=addNum;
curr = head;
while(curr->next != NULL){
curr = curr->next;
}
curr->next = n;
}
}
void List::printList(){
curr=head;
cout << "\n\t\t\t\t CUSTOMER INFO" << endl << endl;
cout <<"NAME" << setw(20) << "SURNAME" << setw(20) << "ID NO. " << setw(20) << "NATIONALLITY" << setw(20) << "TELEPHONE" << endl << endl;
while(curr != NULL){
cout << curr -> name << setw(20) << curr -> surname << setw(20) << curr -> idNum << setw(20) << curr -> nationality << setw(20) << curr -> number << endl << endl;
curr=curr->next;
/*cout<<curr->number << endl;
cout<<curr->age << endl;
cout<<curr->idNum << endl;
cout<<curr->name<< endl;
cout<<curr->surname << endl;
cout<<curr->nationality << endl;
curr = curr->next;
}
*/
}
}
void List::write_linky(string name,string surName,int idNum,string nation,int number)
{
fp.open("Link.dat",ios::out|ios::app);
lb.AddNode(name,surName,idNum,nation,number);
lb.printList();
fp.write((char*)&nod,sizeof(node));
fp.close();
cout<<"\n\nThe Data Has Been Added ";
}
void List::read_linky(){
fp.open("Link.dat",ios::in);
while(fp.read((char*)&nod,sizeof(node)))
{
lb.printList();
//cout<<"\n\n=====================================================\n";
//getch();
}
fp.close();
//getch();
}
int main(){
List lb;
int idNum,number;
string name,surname,nationality;
char choice,ch;
cout<<"Please select your choice"<<endl;
cout<<"1.Book ticket"<<endl;
cout<<"2.view details"<<endl;
cin>>ch;
switch(ch){
case '1':
do{
cout<< "Enter name: ";
cin>>name;
cout<< "Enter surname: ";
cin>>surname;
cout<< "Enter identification number: ";
cin>>idNum;
cout<< "Enter your nationality: ";
cin>>nationality;
cout<< "Enter contact number: ";
cin>>number;
lb.write_linky(name,surname,idNum,nationality,number);
//lb.AddNode(number,age,idNum,name,surname,nationality);
cout<<"\n\nDo you want to add more entry?";
cin>>choice;
}while(choice=='y');
break;
case '2':
lb.read_linky();
break;
}
}
//lb.printList();

Answer 1

I've never done this but I'd guess string is a complex structure that doesn't lend itself to being written to disk like this. As a test change these to (say) char[255] and it might be happier.