11 September 2011 01:26:14 PM

NOT_ALLOCATED_ARRAYS
  C++ version

  When an array starts out as a pointer, you have to use the
  NEW command to allocate memory.  You should always initialize
  such array pointers to NULL, so you can tell if they've been
  allocated or not!

  Unfortunately, when you DELETE an array, you also have to
  reset the pointer to NULL; that does not happen automatically
  either!

  The pointer A is not preset to NULL.
  Before allocation, we check the value:
    a = 0
  The test 'if ( !a )' is not guaranteed to return 1
  because we did not initialize A properly.
    !a = 1
  Now we allocate A.
    a = 0x1002000e0
    !a = 0
  Now we DELETE A.
    a = 0x1002000e0
    !a = 0
  Now we RESET A to NULL!
    a = 0
    !a = 1

  The pointer B is preset to NULL.
  Before allocation, we check the value:
    b = 0
  The test 'if ( !b )' is guaranteed to return 1
  because we initialized B properly.
    !b = 1
  Now we allocate B.
    b = 0x1002000e0
    !b = 0
  Now we DELETE B.
    b = 0x1002000e0
    !b = 0
  Now we RESET B to NULL!
    b = 0
    !b = 1

NOT_ALLOCATED_ARRAYS:
  Normal end of execution.

11 September 2011 01:26:14 PM