char function

hey,
This should be pretty simple:

I need to make a function which returns a person's name from a file

Code:

---


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

char loadName(char def[100])
{
char r[20];
ifstream file(def);
file.getline(r, 20);
return r[0];
}


int main()
{
char name[20];
char def[100] = "c:\\test.txt";

cout << loadName(def);
cin.get();
}

---

What ends up happening is, I have to return the first letter of the person's name, I can't just go
return r;

How would I be able to return a string as opposed to just one char

Thanks in advanced

Well of course since you are using C++, you could be using STL strings - which make life a lot easier. But obviously you're learning with C-style strings, so we'll keep using them. When you're more comfortable with C++, you might want to have a look at STL strings.

The best way to return a string is to return a pointer to the first element of the array.

Code:

---

char *pointer = &r[0];
return pointer;

---

If you haven't learned about pointers yet, now might be a good time to do so - try the tutorial on this site. They may not make sense at first, but stick with it - they're useful, no matter how pointless (no pun intended) they seem at first.

When your other function gets this pointer it can use it to get the string. You can also just pass cout the pointer and it'll print the string to the screen.

Quote:

---

I can't just go
return r;

---

Actually, you can and should - that code would actually return a pointer to the first element of the array! There's your little-known C++ fact of the day.

You might be able to try strncpy(), but I'm not very familiar with the C functions so I cant say for sure.

ok,
I learned pointers.
I still have the same problem though.
I can only return one array
so I used this code:

Code:

---


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

char loadName(char def[100])
{
char r[20];
ifstream file(def);
file.getline(r, 20);
char *pointer = &r[0];
return *pointer;
}

int main()
{

def[100] = "c:\\test.txt";


cout << loadName(def);
cin.get();
}

---

as you can see this only returns first letter. I need to return the entire string. Thanks

Here's one way.

Code:

---

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

char loadName(char def[100], char name[])
{
ifstream file(def);
if (!file.is_open())
{
  cout << "Unable to open file: " << def << endl;
  exit(1);
}
file.getline(name, 30);
}

int main()
{

char def[100] = "c:\\test.txt";
char name[30];

loadName(def, name);
cout << name << endl;
cin.get();
}

---