Reading file into object array C++ - c++

Question

I have to read from a data file which is formatted like this
abcd(string) 1(int) 2(int) 3(int)
abcde(string) 4(int) 3(int) 2(int)
.
.
.
I want to perform some functions which use the variables in the same line only. But here's my code. I'm a beginner so please correct me thank you.
in the .h file
#include <string>
using namespace std;
#ifndef CALC_H
#define CALC_H
class Calc
{
public:
void readFile(string file);
private:
string name;
int a;
int b;
int c;
};
#endif
in the implementation file
#include "Vehicle.h"
#include iostream>
#include fstream>
#include string>
#include cstdlib>
#include cmath>
using namespace std;
void Vehicle::readFile(string filename)
{
ifstream myIn;
int totalNum=0;
myIn.open(filename.c_str());
if (!myIn)
{
cerr<<"Data file failed to open!\n";
exit (0);
}
for (int i=0; i<MAX; i++)
{
while (myIn.peek() != EOF)
{
myIn>>calc[i].name;
myIn>>calc[i].a;
myIn>>calc[i].b;
myIn>>calc[i].c;
totalNum++;
}
}
myIN.close();
and then I want to display what i just read from the file
for (int i = 0; i < MAX; i++)
cout << calc[i].name << calc[i].a << calc[i].b << calc[i].c << endl;
sorry I left out alot of stuff I just want to know if I on the right path. Thanks

Answer 1

The proper way to do this is to overload the >> operator for your class Calc.
class Calc {
public:
friend istream& operator >>(istream& myIn, Calc& calc);
};
istream& operator >>(istream& myIn, Calc& calc) {
myIn >> calc.name;
myIn >> calc.a;
myIn >> calc.b;
myIn >> calc.c;
return myIn;
}
Now you can just do:
while (myIn >> calc[i]) {
++totalNum;
}

Answer 2

You should consider designing it a bit differently.
create a class that holds one line i.e. string int int int - like you have it in "Calc" but without making it dependent on how you create a line (readfile). Lets call it "Line"
class Line
{
public:
std::string name;
int a;
int b;
int c;
};
Now since you need to read several lines you will need some kind of container to hold them, create a vector of Line (or some other container)
std::vector<Line> contents;
then override the stream operator as Tushar suggested so when you read from a file (or from e.g. stdin) you can create instances of Line for each line you read, these instances you use to fill the 'contents' array
now you can start doing whatever it is you want to do with the lines i.e. the actual operation calc