Do...Loop迴圈

'Do...Loop Statements
'   execute a program block repeately while a Boolean Condiltion is true or else it exits the loop.
'   The general form is
'       DO[{WHILE|UNTIL} condition]
'       [statements]
'       [Exit Do]
'       [statements]
'       LOOP[{WHILE|UNTIL} condtion]
'   There are four ways of writing this loop. Two ways use WHILE, the other two ways use UNTIL.
'   WHILE counts from bottom to top and UNTIL counts from top to bottom.


Sub Main()

   
Dim x As Short
    x=
1
   
Do While x<5
       
Debug "*"
        x+=
1        'display 4 asterisks
    Loop
   
   
Debug CR        'moves to next line
    x=1
   
Do
       
Debug "*"
        x+=
1        'display 4 asterisks
    Loop While x<5
   
   
Debug CR
    x =
5
   
Do Until x=0
       
Debug "*"
        x-=
1        'display 5 asterisks
    Loop
   
   
Debug CR
    x =
5  
   
Do
       
Debug "*"
        x-=
1        'display 5 asterisks
    Loop Until x=0
End Sub