Declares an infinite programming loop.
Do
// program segment
Loop
Do...Loop is an endless loop which can only be terminated by the conditional command Exit If or unconditional command Exit Do.
OpenW # 1
Local r
Do
r = 0
Input "Enter radius";r
If r < 0 Then Exit Do
Print "The circumference of the circle is: "; 2 * PI * r
Loop
Print "End of program!"
The program requests the user to enter the radius of a circle. If the entered value is greater than or equal to zero, the circumference of the circle is calculated and displayed.
You are then requested to enter another value. If you enter a negative value the loop is terminated and "End of program!" is displayed.
The Do...Loop statement is the most universal programming loop and it can be used to emulate all other loops:
| i% = 0 | For i%=1 To n% |
| Do | // programsegment |
| If i% > n% Then Exit Do | |
| // programsegment | |
| Loop | Next |
| Do | While Inkey$ <> "A" |
| If Inkey$ = "A" Then Exit Do | // programsegment |
| // programsegment | |
| Loop | Wend |
| Do | Repeat |
| // programsegment | // programsegment |
| If Inkey$ = "A" Then Exit Do | Until Inkey$ = "A" |
| Loop |
Even more powerful loop conditions can be created by combining the Do...Loop with the evaluation part of the While...Wend and/or Repeat...Until loops:
Local a$ = "ABCDE...Z", b$, n%
Do Until n% > Len(a$)
Inc n%
b$ = Mid$(Trim$(a$), n%, 1)
Print b$;
Loop While Upper$(b$) <> "."
Reads a sequential character from string a$, until the end of the string is reached and while the character string starts with something other than a full stop.
OpenW 1
Do While MouseK = 0 : Loop
Do While (MouseK And 1)
Box MouseX, MouseY, Add(MouseX, 10), Add(MouseY, 10)
Loop Until Upper$(InKey$) = "A"
When the left mouse button is pressed it draws a rectangle at the current mouse position, until a lowercase or uppercase "a" is typed on the key-board.
The following loop combinations are possible:
Do ... Loop
Do ... Loop Until
Do ... Loop While
Do ... Wend
Do ... Until
While ... LoopDo While ... Loop
While ... Loop UntilDo While ... Loop Until
While ... Loop WhileDo While ... Loop While
While ... WendDo While ... Wend
While ... UntilDo While ... Until
Repeat ... LoopDo Until ... Loop
Repeat ... Loop UntilDo Until ... Loop Until
Repeat ... Loop WhileDo Until ... Loop While
Repeat ... WendDo Until ... Wend
Repeat ... UntilDo Until ... Until
Do ... Loop
Do ... Loop Until
Do ... Loop While
Do ... Wend
Do ... Until
For Next, While Wend, Repeat Until
{Created by Sjouke Hamstra; Last updated: 03/10/2014 by James Gaite}