Refrencing to make 2D array of variable size

[igotabuginmyeye]

Am having trouble getting my references to change the size values of an array.

The goal is to accept a user input and use that to assign a size to my array (with the eventual aim of being able to output shapes of a size input by a user, within an array)

Sorry if any of my lingo's off or I haven't provided enough info, newbie! I've attached the entirety of my code to hopefully minimize confusion!

#include <iostream>
#include <string>

using namespace std;

int main ()
{

	int size;

	cout << "Please enter the size of your diamond: ";
	cin >> size;
	cout << endl;

	int center = size;
	int rowStart = 0;
	int rowEnd = rowStart + (center - 1);
	int rowMid = rowStart + (center/2);
	int colStart = rowMid;
	int colEnd = colStart+1;

	char display [1][1];
	{
	char* display [1][1] = new char[size][size]; /* this line */
                                                     /* causes problems? */

		for(int r = rowStart; r < rowMid; r++ )
		{
			for(int c = colStart; c < colEnd ; c++)
			{
				display[r][c] = '*';
			}

			colStart--;
			colEnd++;
		}
	}
}

I hope this shows what i'm trying to achieve here!

[freddy92]

Just gonna start by pointing out some lines that need deleted:

	char display [1][1];  // not sure why this exists
	{ // what's this for?
	char* display [1][1] = new char[size][size]; /* this line */
                                                     /* causes problems? */

		for(int r = rowStart; r < rowMid; r++ )
		{
			for(int c = colStart; c < colEnd ; c++)
			{
				display[r][c] = '*';
			}

			colStart--;
			colEnd++;
		}
	} // what's this for?
} 

Now as for dynamically allocating a 2D array, it's possible but you should really use a vector if you know what those are. Here's how to allocate a 2D character array:

char** display = new char*[size]; //declare a pointer to a char pointer
for (int i = 0; i < size; i++)             //loop through this array
          display[i] = new char[size];//each index becomes a new char array 

After that you can use display like a normal 2D array, like display[i][k] or whatever you want to do. Be sure to delete all the allocated memory when you're done though (you'll need to loop through the array again).