Loading text from a file into a 2-dimensional array (C++)

Question

I'm making a game and I have stored the map data in a 2-dimensional array of size [34][10]. Originally I generated the map using a simple function to fill up the array and saved this data to a file using the following code:

ofstream myFile;
myFile.open("map.txt");

for ( int y = 0 ; y < MAP_HEIGHT ; ++y )
{
 for ( int x = 0 ; x < MAP_WIDTH ; ++x )
 {
  myFile << m_acMapData[x][y];
 }
 myFile << '\n';
}

myFile.close();

This outputs a text file which looks something like how I want it to. However, when I try to read it back in using the following code, I get a load of access violations and it crashes at runtime:

ifstream myFile;
int i=0;
int j=0;
char line[MAP_WIDTH];

myFile.open("map.txt");
while (!myFile.eof())
{
 myFile.getline(line, MAP_WIDTH);
 for ( i=0; i<MAP_WIDTH; i++ )
 {
  m_acMapData[i][j] = line[i];
 }
 ++j;
 cout << line;
}

Does anyone know what the problem is?

Answer 1

while (!myFile.eof())
{
        myFile.getline(line, MAP_WIDTH);

should be:

while ( myFile.getline(line, MAP_WIDTH) )
{

It would however be safer to read into a std::string:

string line:
while ( getline( myFile, line ) )
{

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Answer 2

Ya i will definately crash because you are doing wrong here.

ofstream myFile; myFile.open("map.txt");

for ( int y = 0 ; y < MAP_HEIGHT ; ++y ) {

    for ( int x = 0 ; x < MAP_WIDTH ; ++x )
    {

            myFile << m_acMapData[x][y];

    }

    myFile << '\n';

}

myFile.close();

Suppose MAP_HEIGHT = 3 and MAP_WIDTH = 6 ;

And you must know that array in C/C++ is row major so when you try to access

m_acMapData[4][0] it would accessing memory out of its range.

So do something like this:

for ( int y = 0 ; y < MAP_HEIGHT ; ++y ) {

    for ( int x = 0 ; x < MAP_WIDTH ; ++x )
    {

            myFile << m_acMapData[y][x]; // here to be changed

    }

    myFile << '\n';

}