getline() function is not working in while loop - c++

Question

I want to make a simple file input output program with an external class "File_Opening_and_Closing.cpp” when I use ”getline ()” function without any loop it works fine but when I use ”getline ()” function with do while loop in “main.cpp” it crushes.
Please tell me where the problem is and how I solve it?
main.cpp
#include<iostream>
#include<fstream>
#include "File_Opening_and_Closing.h" using namespace std;
int main() {
int i=1;
char file_make='y';
char file_insert='y';
do
{
File_Opening_and_Closing file[i];
do
{
file[i].put_data();
file[i].show_data();
cout<<"Do you want to insert text again ? 'y' OR 'n'"<<endl;
cin>>file_insert;
}while(file_make=='y');
i++;
cout<<"Do you want to Make another file ? 'y' OR 'n'"<<endl;
cin>>file_make;
}while(file_insert=='y');
return 0;}
with out loop working fine >>
int main() {
File_Opening_and_Closing file;
file.put_data();
file.show_data();
return 0;}
File_Opening_and_Closing.cpp
#include "File_Opening_and_Closing.h"
File_Opening_and_Closing::File_Opening_and_Closing()
{
cout<<"Enter the file name and type => ";
cin>>file_name;
}
void File_Opening_and_Closing::put_data(){
ofstream file_out;
file_out.open(file_name);
cin.ignore();
cout<<"Enter the string => ";
cin.ignore();
// getline is not working here!
getline(cin,data);
data = "Hello World!";
file_out<<data;
file_out.close();
}
void File_Opening_and_Closing::show_data(){
ifstream file_in;
file_in.open(file_name);
getline(file_in,data);
cout<<data;
file_in.close();
}
File_Opening_and_Closing.h
#ifndef FILE_OPENING_AND_CLOSING_H
#define FILE_OPENING_AND_CLOSING_H
#include<iostream>
#include<fstream>
using namespace std;
class File_Opening_and_Closing
{
private:
string file_name;
string data;
public:
File_Opening_and_Closing();
void put_data();
void show_data();
protected:
};
#endif // FILE_OPENING_AND_CLOSING_H
Problem picture

Answer 1

You have a whole host of issues, not the least of what is a How to debug small programs issue where you have mixed up the variables used to test both do .. while (...); loops, e.g.
...
cin>>file_insert;
}while(file_make=='y');
// i++; (not needed and VLA's not allowed in C++
cout<<"Do you want to Make another file ? 'y' OR 'n'"<<endl;
cin>>file_make;
}while(file_insert=='y');
Secondly, as mentioned in the comments, Standard C++ does not allow Variable Length Arrays.
File_Opening_and_Closing file[i];
If you need more than 1 instance of your class, the use a vector of classes or array of classes. However, there is no need in your code for either. Since you create a new instance of File_Opening_and_Closing each iteration through the do { ... } while (..); loop, you can simply use:
File_Opening_and_Closing file;
You are making things incredibly hard on yourself by declaring file_make and file_insert as type char. Instead, simply make them std::string and test with, e.g. if (file_make == "y"). This will allow you to read all input with getline avoiding the problems with mixed std::cin and getline use.
The remaining issues are a complete failure to validate the file openings with, e.g. if (!file_out.is_open()) { /* handle error */ } with similar tests needed for each input to ensure you can trap a input cancellation by the user generating a manual EOF with Ctrl+d (or Ctrl+z on windows).
Also, avoid putting using namespace std; in header files. There is no need to pull the standard namespace into every file utilizing your header (though you did do a good job and protect against multiple inclusions with the header guards FILE_OPENING_AND_CLOSING_H). In fact there is no reason for using namespace std; at all here. Just use the std:: namespace resolution operator for cin, cout, etc..
Leaving the validations for you to add, addressing the other issues, you could do something similar to:
File_Opening_and_Closing.h
#ifndef FILE_OPENING_AND_CLOSING_H
#define FILE_OPENING_AND_CLOSING_H
#include<iostream>
#include<fstream>
class File_Opening_and_Closing
{
private:
std::string file_name;
std::string data;
public:
File_Opening_and_Closing();
void put_data();
void show_data();
protected:
};
#endif
File_Opening_and_Closing.cpp
#include "File_Opening_and_Closing.h"
File_Opening_and_Closing::File_Opening_and_Closing()
{
std::cout << "Enter the file name and type => ";
getline (std::cin, file_name);
}
void File_Opening_and_Closing::put_data(){
std::ofstream file_out;
file_out.open(file_name);
std::cout<<"Enter the string => ";
getline (std::cin, data);
file_out << data << '\n';
file_out.close();
}
void File_Opening_and_Closing::show_data(){
std::ifstream file_in;
file_in.open (file_name);
getline (file_in,data);
std::cout << data << '\n';
file_in.close();
}
main.cpp
#include<iostream>
#include<fstream>
#include "File_Opening_and_Closing.h"
int main (void) {
std::string file_make = "y";
std::string file_insert = "y";
do
{
File_Opening_and_Closing file;
do
{
file.put_data();
file.show_data();
std::cout << "Do you want to insert text again ? 'y' OR 'n'\n";
getline (std::cin, file_insert);
} while (file_insert == "y");
std::cout << "Do you want to Make another file ? 'y' OR 'n'\n";
getline (std::cin, file_make);
} while (file_make == "y");
return 0;
}
It will now create as many files as you need (though you will want to look into std::ios::app mode if you want to add more than one string.
Example Use/Output
$ ./bin/main
Enter the file name and type => out1
Enter the string => foobar
foobar
Do you want to insert text again ? 'y' OR 'n'
y
Enter the string => barbaz
barbaz
Do you want to insert text again ? 'y' OR 'n'
n
Do you want to Make another file ? 'y' OR 'n'
y
Enter the file name and type => out2
Enter the string => bazbuz
bazbuz
Do you want to insert text again ? 'y' OR 'n'
n
Do you want to Make another file ? 'y' OR 'n'
n
Resulting Output Files
$ cat out1
barbaz
$ cat out2
bazbuz
Let me know if you have further questions.