copy objec from file to array or vector

[peha]

Hi all!

I have a file containing information of person like:

name(string) age(int) gender(char) .....

as an object attribute like let say perobj as an object from Person class.

know i want to know how to create an array of Person class let say Person myperson[] and copy all objects from file to array.


ps:vector or list is OK also!

thanks

[helios]

Could you give an example of one of the "objects" in the file?

[peha]

wow fast reply!

file looks like this!
data.txt:

Jack 23 M
Maggy 40 F

so i want to copy this data in an array like Person per[]

so i can use statement like this

per[0].getneme() or something like per[1].setname("Mary") and so on...

I just noticed that i want to rewrite the edited information in the same file!!!!

[helios]

wow fast reply!

You were lucky. Weekends are slow.

Are you expecting to have spaces in the name, or will the name always be exactly one word?

[peha]

let it be one word!

[Bazzy]

Why don't you overload the >> operator to get data into your class?

[peha]

you mean something like this?

Person perobj[];//how to find the number of objects?, it should be the number of line in the file
int i=0;

while(!data.eof()){

data>>perobj[i].setname()>>perobj[i].setage()>>perobj[i].setgender();
i++;
//here is one of my problems! don't know how to go to the next line
}

[Bazzy]

Not really.
In your class:

class Person
{
    // some members ...

   friend std::istream &operator >> ( std::istream &, Person & ); // so that >> can access private members
};

operator >> implementation:

std::istream &operator >> ( std::istream &is, Person &pers)
{
    is >> pers.name >> pers.age >> pers.gender; // use directly member variables, not setter functions
   return is;
}

While reading -let's say you have a list-:

Person temp; // declare temporary Person object
data >> temp; // read it from the file
person_list.push_back ( temp ); // add it to the list - this way data could contain any number of people 

[peha]

brilliant solution!!

and i can do same thing for copying in file with overloading << operator hmmm..!

but why you use class private members directly instead of using setter functions? does it have any reason or its just good programming habit!

[Bazzy]

It is faster:
with friend:

operator >> etc
{
    is >> pers.member;
}

without friend:

operator >> etc
{
    type temp;
    is >> temp;
    pers.set_member ( temp );
}

[peha]

Thanks so much dude!