Return Array Function

[marsh]

Hello, i am new to c++ so i hope you guys can help me out. I have searched the answer up on google and while i find examples i cant quite understand whats going on yet. I want to make a simple file read function so i dont have to keep reading a file in 100 different places in my program.

Here is what i have, it is very simple and obviously wrong. It is supposed to read the file and store it in a array (which it does) and then return the array so i can use the data.

string ReadWrite(char * FileName)
{
	int i = 1;

	// String to hold all the file lines in
	string line[50];
	string FileContent;

  ifstream myfile (FileName);
  if (myfile.is_open())
  {
    while ( myfile.good() )
    {

	  // Read a line out of the file
      getline (myfile,line[i]);

	  // Increase the Array by one so we dont overwrite
      ++i;
    }
    myfile.close();
  }

  else cout << "Unable to open file"; 

return line[];
}

Any help is greatly appreciated. Sorry for messy formatting.

[Chris_F]

Why not try something like this:

int LoadText(const std::string& filename, std::string& buffer)
{
    std::ifstream fs(filename);
    if (!fs) return -1;
    std::copy( std::istreambuf_iterator<char>(fs), 
        std::istreambuf_iterator<char>(), 
        std::back_inserter(buffer) );
    return 0;
}

std::string filetext;
if ( LoadText("somefile.txt", filetext) )
{
    std::cout << filetext;
}
else
{
    std::cout << "Couldn't open file!";
}

If you really want to access the text by indexing by line number, then maybe something like this:

int LoadText(const std::string& filename, std::vector<std::string>& buffer)
{
    std::ifstream fs(filename);
    if (!fs) return -1;
    std::string line;
    while ( std::getline(fs, line) )
    {
        buffer.push_back(line);
    }
    return 0;
}

std::vector<std::string> filetext;
if ( LoadText("somefile.txt", filetext) )
{
    std::cout << filetext[0]; //first line
}
else
{
    std::cout << "Couldn't open file!";
}

[marsh]

Thanks a lot for the help . I realize i may have posted this in the wrong section because i am using Visual C++ and it has given me errors in the past with strings.

I am getting this error:

cannot convert parameter 1 from 'const std::string' to 'const char *'


I tried making it a cont char * and though it will run it crashes immediately on the second example code and does nothing on the first. Anyway you can help me out again? or should i be making a thread in the Visual C++ board?

[Eri523]

There is no implicit conversion from std::string to const char *. Moreover, they are basically incompatible so doing a simple serach-and-replace between the two is an almost 100% certain way to ruin your program.

However, there is a member function of std::string called c_str() which does exactly the conversion you want. You just need to call it explicitly.

EDIT: And note that this is all standard stuff and should apply likewise to any (decent) compiler.

[marsh]

Yea i was 90% certain it would not work but i gave it a shot. Thank you for the c_str()