How get value for unchecked checkbox in checkbox elements when form posted?

Question

I have a form like below :

Answer 1

First way - hidden fields (disadvantage: the user can manipulate the value of the field (but one can manipulate the value of the checkbox too, so it's not really a problem, if you only expect 1 or 0))

 string '0' (length=1)
  'status_2' => string '1' (length=1)
  'status_3' => string '0' (length=1)
 */

Second way - to assign default value for non-set indexes:

 string '1' (length=1)
  'status_1' => int 0
  'status_2' => int 0
 */