so it was only the issue of std::string class, thanks i succeed with the following code.

#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;

class Data
{
public:
char name[20];
int id;
public:
Data(){}
Data(char *n,int id){strcpy(name,n);this->id=id;}
};

int main() {

Data objdata;
//fstream file("c:\\\\test.txt",ios::out | ios::binary);
fstream file("c:\\\\test.txt",ios::in | ios::binary);
if(file.is\_open())
{
	//file.write((char\*)&objdata,sizeof(Data));

	file.read((char\*)&objdata,sizeof(Data));
	cout<<objdata.name<<objdata.id;
	cout<<"Success";
	file.close();
}
else
{
	cout<<"Error";
}

return 0;

}

i'm writing a simple program using Ansi C++. I'm not using Microsoft C++. that doesnot applies to me. what's your suggestion?

your question is not so clear. provide some code so that it can be answered.

Writing Object Succeeds with the following code

#include <iostream>
#include <fstream>
using namespace std;

class Data
{
public:
string name;
int id;
public:
Data(){}
Data(string n,int id){name=n;this->id=id;}
};

int main() {

Data objdata("sujan dhakal",1);
fstream file("c:\\\\test.txt",ios::out | ios::binary);
if(file.is\_open())
{
	file.write((char\*)&objdata,sizeof(Data));
	cout<<"Success";
	file.close();
}
else
{
	cout<<"Error";
}

return 0;

}

but why reading not working #include <iostream> #include <fstream> using namespace std; class Data { public: string name; int id; public: Data(){} Data(string n,int id){name=n;this->id=id;} }; int main() { Data objdata; fstream file("c:\\test.txt",ios::in | ios::binary); if(file.is_open()) { file.read((char*)&objdata,sizeof(Data)); cout<<objdata.name<<objdata.id<<endl; cout<<"Success"; file.close(); } else { cout<<"Error"; } return 0; } help me

#include <iostream> #include <fstream> using namespace std; int main() { char data[5];//={'a','b','c','f','\0'}; //fstream file("c:\\test.txt",ios::out | ios::binary); fstream file("c:\\test.txt",ios::in | ios::binary); if(file.is_open()) { //file.write(data,sizeof(data)); while(!file.eof()) { file.read(data,sizeof(data)); cout<<data; } file.close(); } else { cout<<"Error"; } return 0; } I've written "abcf" to text.txt file in binary mode. i'm reading back the data into the variable "data". why the heck the output is "abcfabcf". I should be "abcf" but what happened to this one. and another question do anybody knows how to write and read string data-type in binary mode. please help.

what's problem with this bit masking ios::in | ios::out | ios::binary since we have specified out in the mask, why the file is not being created. thanks for replying.

thanks for the answer but i dont want to use ofstream and ifstream class instead i want to use fstream class only. Is it possible? and i also need the file to be created as using ofstream.

no the file is expected to be created. in the following case also it outputs "Error" fstream file("c:\\test.txt",ios::out | ios::in); if(file.is_open()) { file<<"Hello"; file.close(); } else { cout<<"Error"; }

#include <iostream> #include <fstream> using namespace std; int main() { fstream file("c:\\test.txt",ios::in | ios::out | ios::binary); if(file.is_open()) { file<<"Hello"; file.close(); } else { cout<<"Error"; } return 0; } I wonder why this code is giving me the output "Error" unexpectedly...what went wrong in this code. I'm not able to write texts in file..please help