Create 2D array by passing pointer to function in c

Question

So I read dozens of examples of passing an 2D array pointer to function to get/change values of that array in function. But is it possible to create (allocate memory) inside

Answer 1

Forget about pointer-to-pointers. They have nothing to do with 2D arrays.

How to do it correctly: How do I correctly set up, access, and free a multidimensional array in C?.

One of many reasons why it is wrong to use pointer-to-pointer: Why do I need to use type** to point to type*?.

Example of how you could do it properly:

#include 
#include 


void* create_2D_array (size_t x, size_t y)
{
  int (*array)[y] = malloc( sizeof(int[x][y]) );

  for (size_t i = 0; i < x; ++i) 
  {
    for (size_t j = 0; j < y; ++j) 
    {
      array[i][j] = (int)(i + j);
    }
  }

  return array;
}

void print_2D_array (size_t x, size_t y, int array[x][y])
{
  for (size_t i = 0; i < x; ++i) 
  {
    for (size_t j = 0; j < y; ++j) 
    {
      printf("%d ", array[i][j]);
    }
    printf("\n");
  }
}


int main (void)
{
  size_t x = 5;
  size_t y = 3;

  int (*arr_2D)[y];

  arr_2D = create_2D_array(x, y);

  print_2D_array(x, y, arr_2D);

  free(arr_2D);

  return 0;
}