reading integer from file

[ebii]

how can i put all integers that i read from files into array seems i have a bit trouble here it alwys print the last integer value

 int main() {
	fstream file;
	int array[4];
	int x;
	file.open("o.txt");

	while (file>>x) {
		cout << x << endl;
		for (int i = 0; i < 4; i++) {
			array[i] = x;
		}
		}
	for (int i = 0; i < 4; i++) {
		cout << array[i] <<' ';
	}
	
	

	file.close();
	system("pause");
	return 0;
}

file:
100
90
40
30
121

[Chervil]

Your array is too small to hold the entire contents of the file. You should also keep track of how many values have been read from the file - it may not be the same as the array size. (but cannot be greater).

int main() 
{

    // make size at least as large as needed
    const int size = 20;
    int array[size];

    
    ifstream file("o.txt");
 
    int count = 0; 
    int x;

    // check that array is not already full
    // and read integer from file, 
         
    while (count < size && file >> x) 
        array[count++] = x;


    // display the values stored in the array
    for (int i = 0; i < count; i++)
        cout << array[i] <<' ';
    
}

[ebii]

tnx alot mate..
i already mange to fix it .
but have another quastion if you can help
how to write object to txt file.

class Student {
	string name;
	int score;
public:
	Student() {}
	void setdata() {
		cout << "Enter name" << endl;
		cin >> name;
		cout << "Enter score" << endl;
		cin.ignore(1000, '\n');
		
	}


};
int main() {
	fstream file;
	file.open("student.txt");
	int i = 0;
		Student s;
		s.setdata();
		file << s;    //???

		system("pause");
		return 0;


}

[Chervil]

A convenient way to do that sort of thing is to overload the input and output operators >> and << for the Student class:

class Student {
    string name;
    int score;
    
public:
    Student() {}
    void setdata() {
        cout << "Enter name" << endl;
        getline(cin,name);
        cout << "Enter score" << endl;
        cin >> score;
        cin.ignore(1000, '\n');
        
    }


    friend ostream & operator << (ostream & os, const Student & s)
    {
        os << s.name << '\t' << s.score;
        return os;
    }


    friend istream & operator >> (istream & is, Student & s)
    {
        getline(is, s.name, '\t');
        is >> s.score;
        is.ignore(10, '\n');
        return is;
    }

};

int main() 
{
    ofstream file("student.txt");
    
    Student s;
    
    for (int i=0; i<3; ++i)
    {
        s.setdata();
        file << s  << '\n';  
    }
      
    file.close();
    
    cout << "\n reading from file:\n";
    
    ifstream fin("student.txt");
    while (fin >> s)
        cout << s << '\n';
    
}

[ebii]

thanks alot man helpd alot