Question

  $row[];  // Declare array. PRETEND ITS AN ARRAY
  $row2[]; // Declare another
  $row3[]; // Declare one more

  $rowarray[];

  $rowarray[0] = $row
  $rowarray[1] = $row2
  $rowarray[2] = $row3 // Store array in an array

My Questions:
1. Is this valid or even useful?
2. If I do this, how do I access $row[0] $row[1] etc.

Answer 1

1. The concept is valid, but the syntax is not — arrays are not explicitly declared like that in PHP. A correct way to initialize this would be something like:

   $row1 = array(1, 2, 3);
   $row2 = array(4, 5, 6);
   $row3 = array(7, 8, 9);
   $rowarray = array($row1, $row2, $row3);
   

   Or, equivalently and more succinctly:

   $rowarray = array(
       array(1, 2, 3),
       array(4, 5, 6),
       array(7, 8, 9)
   );
   

2. $rowarray[1][2]. Indexes are in order, so, given the example data I used, this would be 6 (element 2 of the array which is element 1 of $rowarray).