Add record to file and read it back - c++

Question

#include <iostream>
#include <fstream>
#include <string>
#include <cstring>
using namespace std;
class Book
{
public:
char ISBN [5];
char Title [20];
char authorName [20];
char Price [10];
char Year [10];
char NumOfPages [10];
char delimiter = ',';
};
void AddBook ()
{
fstream file;
file.open("Records.txt", ios::out|ios::app);
Book b;
cout << "Enter ISBN: " << endl;
cin>>b.ISBN;
cin.ignore();
cout << "Enter Title: " << endl;
cin.getline(b.Title,sizeof(b.Title));
cout << "Enter Author's Name: " << endl;
cin.getline(b.authorName , sizeof(b.authorName));
cout << "Enter Price: " << endl;
cin.getline(b.Price,sizeof(b.Price));
cout << "Enter Year: " << endl;
cin.getline(b.Year,10);
cout << "Enter Number Of Pages: " << endl;
cin.getline(b.NumOfPages , sizeof(b.NumOfPages));
cin.ignore();
file.write(reinterpret_cast<char*>(&b), sizeof(b));
file.write(reinterpret_cast<char*>(&b.delimiter), sizeof(b.delimiter));
file.close();
}
void DeleteBook ()
{
}
void UpdateBook ()
{
}
void PrintBook ()
{
}
void PrintAll ()
{
ifstream file;
file.open("Records.txt", ios::in);
Book b;
while (!file.eof())
{
cout << "ISBN :" << b.ISBN <<endl;
cout << "Title :" << b.Title <<endl;
cout << "Author's Name :" << b.authorName <<endl;
cout << "Price :" << b.Price <<endl;
cout << "Year :" << b.Year <<endl;
cout << "Number of Pages "<< b.NumOfPages <<endl;
file.read(reinterpret_cast <char*> (&b), sizeof(b));
}
file.close();
}
int main()
{
int choice;
do
{
cout << "The Menu for Book Store" << endl;
cout << "1. Add Book: " << endl;
cout << "2. Delete Book: " << endl;
cout << "3. Update Book:" << endl;
cout << "4. print a Book:" <<endl;
cout << "5. print all Books " << endl;
cout << "6. Exit the program "<<endl;
cout << "Enter your choice here "<<endl;
cin >> choice;
switch (choice)
{
case 1:
AddBook();
break;
case 2:
DeleteBook();
break;
case 3:
UpdateBook();
break;
case 4:
PrintBook();
break;
case 5:
PrintAll();
break;
default:
cout << "Invalid Selection" << endl;
}
}
while
(choice != 6);
return 0;
}
The output looks strange in file and the output is being outputted twice on in strange chars and the other is good but ISBN is attached to title i need a solution please how i can fix it as it's not obvious where's the logical error here for me
Output
ISBN :
╞3╧v`≡o F╙v└²a
Title :
≡o F╙v└²a
Author's Name
:
Price :
F╙
Year :
oÇ≡o╘≡o   
 
Number of Pages   
 
ISBN :12345Jungle House
Title :Jungle House
Author's Name :ASad asad
Price :240
Year :2019
Number of Pages 300

Answer 1

You have many problems with the code you show, but the reason for the seemingly garbage output is that your printAll function you print the data in the Book object b before you read anything into it.
That means the object b isn't initialized yet, and will contain indeterminate data (which might seem like random or garbage). Using such values in any way leads to undefined behavior.