Passing a 2D array to a Function in C++

Question

So here's my question as I have been looking over the internet for a while but can't seem to get a clear answer to make it work. I am working on creating a simple sokoban game in C++ using the Console.

First of all, I am pretty sure that it is not a good idea to pass an array to a function due to the memory intensity if it is a large array. All fine and good, that should not be a problem as I only have a maximum of up to about 32x41 and I'm not even going to get to the maximum. So should I pass the whole array or should I pass pointers?

Secondly, My array size is not always the same. I'm not sure if this is an important factor or not.

Thirdly, If I'm going to be passing pointers, how do I create/initialise them before I start working with them. My array was created in the following manner:

string line;
string arr[30];
int i = 0;
char mazeArr[30][40];
int k, count;

if (mazeStream.is_open())
{
  while ( mazeStream.good() && !mazeStream.eof() )
  {
      getline (mazeStream,line);
      cout << line << endl;
      arr[i] = line;
      i++;
  }
  mazeStream.close();
  cout << endl;
}

else cout << "Unable to open file"; 

for ( count = 0; count < 12; count ++)
{
    string::const_iterator iterator1 = arr[count].begin();
     k = 0;

    while (iterator1 != arr[count].end())
    {
        mazeArr[count][k] = *iterator1;
        iterator1++;
        k++;
    }
}

now what I would like to do with this 2D array is:

• take one element at a time and create an instance of a class, depending on the symbol in the array
• place the instance into another array which takes the instance its type

So in the end I will end up with a second array of instances, where each instance is dependent on the symbol I have taken from the first array. while retaining the same 'coordinates'

Any help would be greatly appreciated,

Thanks

Answer 1

I would do something along the lines of this:

char **createMaze(width, height)
{
    // Dynamically allocate memory creating a pointer array of pointers
    char **maze = new char*[width];

    // Loop to allocate memory for each pointer array
    for(int i = 0; i < width; i++)
        maze[i] = new char[height];

    return maze;
}

int main()
{
    width = 40;
    height = 30;
    char **maze = createMaze(40, 30);

    // You can now access elements from maze just like a normal
    // 2D array   maze[23][12]   - You can also pass this into
    // a function as an arugment      

    return 0;
}

This code is untested.. because I wrote it in the browser XD.