Counting Backwards

Statement 2 will be executed after Statement 1:

' Loop with greater than comparison
'
LET COUNT = 4            'Statement 1
'
DO WHILE COUNT  > 0      'Statement 2
  PRINT COUNT            'Statement 3
  LET COUNT = COUNT - 1  'Statement 4
LOOP 
END

Just after Statement 1, Statement 2 will look like:

DO WHILE COUNT  > 0      'Statement 2
          ^
          |
          +----- contains 4

Since 4 > 0 the condition is TRUE and the DO WHILE lets the loop body execute. Statement 3 and statement 4 (the loop body) execute. After they execute, COUNT has the value 3.

Now, since 3 > 0 the condition is TRUE (again) and the DO WHILE lets the loop body execute another time. And so on. Eventually, COUNT is changed to zero (in statement 4). After this happens, the condition is FALSE and the DO WHILE will not let the loop body execute. The program will print out:

4
3
2
1

' Modified Program
'
LET COUNT = 4            'Statement 1
'
DO WHILE COUNT  > 0      'Statement 2
  PRINT COUNT            'Statement 3
  LET COUNT = COUNT + 1  'Statement 4
LOOP 
END