Retrieving a multidimensional array from an array

Question

I'm going crazy with pointers in C at the moment. I have the following two multi-dimensional arrays:

int num0[5][3] =
{ {0,1,0},
  {1,0,1},
  {0,1,0},
  {1,0,1},
  {0,1,0}
};

int num1[5][3] =
{ {1,1,1},
  {1,0,1},
  {0,1,1},
  {0,1,0},
  {1,0,0}
};

These are then packed into another array as such:

int (*numbers[])[3] = { num0, num1 };

If I then do:

printf( "Result: %d\n", numbers[0][2][2] );

I get the expected result, in this case Result: 1.

However, I'd like to assign numbers[0] to another variable. So in a modern programming language, you'd do something as simple as:

int newvar[5][3] = numbers[0];
printf( "Result: %d\n", newvar[2][2] );

Even though my pointer knowledge is limited, I know this isn't going to work (and it of course doesn't). But for the life of me I can't figure out the correct syntax to make it work (and more importantly, understand WHY it works).

If anyone out there can help me out here I'd really appreciate it!

Thanks

With statically allocated arrays, it's not going to be easy. Really, use malloc() and a linked list-style design. That's how it's gonna be easy. — user529758
– user529758, Commented Jun 13, 2012 at 19:59
By the way, the expected results of numbers[0][2][2] is 0 not 1. — Michael Boselowitz
– Michael Boselowitz, Commented Jun 13, 2012 at 20:16

ouah · Accepted Answer · 2012-06-13 20:09:40Z

2

You cannot assign arrays in C, use memcpy to copy arrays:

 memcpy(newvar, numbers[0], sizeof newvar);

answered Jun 13, 2012 at 20:09

ouah

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