assignment error in struct

In the following why do the integer assignments work OK but the char assignment gives an error 'invalid array assignment'?

Code:

#include <windows.h>
#include <iostream>
#include <string>
#include <sstream>

using namespace std;

struct Player
{
        char surname[5];
        char initial[2];
        char firstname[5];
        char club[9];
        int normalgrade;
        int rapidgrade;
        char gradingnumber[9];
        int dmno;
  };

int main ()
{
Player Reed;
Reed.surname = "Reed";
//Reed.initial = "F";
//Reed.firstname = "Mike";
//Reed.club = "Fakenham";
Reed.normalgrade=200;
Reed.rapidgrade=199;
//Reed.gradingnumber="107456D";
Reed.dmno=14171;

cout<<Reed.surname<<endl;
cout<<Reed.rapidgrade<<endl;
cout<<Reed.dmno<<endl;

  return 0;
}

You can not use the assignment operator= with C-strings, maybe you should consider using std::strings instead.

Jim

I tried changing the char [5] to string [5] but that gave another error of incompatible types.

Either use char* instead of char[] so you can use operator= or, use std::strings like this:

std::string Surname;
Surname = "Reed";

string[5] creates an array of 5 strings, not a string with a maximum length of 5 characters.

Why would you need an array of strings? You should just use

Code:

string surname;

Jim

I see the light - I didn't realise you could use string in a struct declaration as all the samples I looked at used char x[] - one more thing to poke into the brain.

You can use anything in a string. It's just a container. (like a class, but less complicated (therefore less powerful) and for C)

What?? A string is a C++ class. If you meant a struct, then in C++ there is little difference between a struct and a class. The only difference is that a struct defaults to public access an a class defaults to private access. In C++ you can have both member functions and variables in either a class or a struct.

Jim

the only time you might want to use char arrays in a struct is if you're writing it to a file, or sending it over a network connection (these are examples - there are other similar situations). there are better ways to do this than with a raw struct, but all of them require much more code.

Originally Posted by Elkvis

the only time you might want to use char arrays in a struct is if you're writing it to a file...

I disagree. I'd serialize the string itself (the >> operator!).

...or sending it over a network connection (these are examples - there are other similar situations)...

Then you are using the Win32 API or similar, which you need to move away from. Quickly.
Boost offers an alternative, but damn, it's complicated (but powerful).
This is clearly one area where Java has the advantage (I'm actually shamed to admit that).

you obviously didn't read the second half of my post, regarding better ways to write to a file than just a simple memory dump of a struct.

I did. I merely pointed out that I would not consider what you suggested as a "one time you might want to do it." Ergo, you never want to do that in C++. Strings can easily be serialized. Char arrays, not so easily.

Originally Posted by Elysia

I did. I merely pointed out that I would not consider what you suggested as a "one time you might want to do it." Ergo, you never want to do that in C++. Strings can easily be serialized. Char arrays, not so easily.

Well, if the record in a record based binary file is guaranteed to be a certain size, then you can do random file I/O instead of working sequentially. If that's your goal then there really isn't much difference this time, because you would have to store the string in a field of some certain size, anyway. And random file I/O is one very common reason to use binary. Your serialization strategy really depends on what the goals are, and for other parts of the code, a std::string is a lot better.

Good point there. I'll just leave it at that.