Thread: Just a quickie

hey,

Just having trouble with creating a 2d array in the heap memory.

my code goes something like this:

twoDarray = new char[iSize][iSize];

where iSize is passed into the method.

cheers,
ActionMan

sorry forgot to say that twoDArray is declared as follows..

char ** twoDarray;

You cannot do it like that. A char** is a pointer to a pointer!

I believe this is what you're looking for...

Code:

char **NewMatrix(int rows, int columns)
{
  char **matrix = new char*[rows];

  while(rows)
  {
   matrix[--rows] = new char[columns];

   memset(matrix[rows], 0, columns);
  }
 return matrix;
}





//...You MUST call this to free up the memory...

void KillMatrix(char** matrix, int rows)
{
  while(rows)
  delete [] matrix[--rows];
}

int main(int argc, char *argv[])
{
int i, rows = 20, cols = 50;

char **strings = NewMatrix(rows, cols);

for(i = 0; i < rows; i++)
sprintf(strings[i], "\nString #%i", i+1);

for(i = 0; i < rows; i++)
 {
  printf(strings[i]);
  getch();
 }

printf("\n\n\nDeallocating Array!");

getch();

KillMatrix(strings, rows);

  return 0;
}