FOR...NEXT's

[jumpboy]

Code:

SUB ball

FOR a = 350 TO 550 STEP 1
FOR b = 375 TO 283 STEP 1

        CIRCLE (a, b), 10, 4
        PAINT (a, b), 4, 4

FOR delay = 1 TO 7500
NEXT delay

        CIRCLE (a, b), 10, 0
        PAINT (a, b), 0, 0


NEXT b
NEXT a

END SUB

I've never been able to figure this out. How can I make these for nexts work like they are? I want a ball to be shot and go though a hoop and and have curve so I thought this would work (but it didn't)

[marinedalek]

The b FOR-NEXT needs to be STEP -1 as it's going down.

[jumpboy]

The code doesn't work for me. Nothing happens. It will run but you can't see anything. When I REM out the b part it will move straight across the screen. When I REM out the a part, nothing happens...

[marinedalek]

as I said, FOR b = 375 TO 283 STEP 1 needs to be FOR b = 375 TO 283 STEP -1
otherwise qbasic just skips the for-next as it has an invalid step.
However, after testing your program I noticed it won't do what you want anyway. it'll rise up, then go down and move along a pixel then rise up again. You'll need some sort of formula to get the curve (or two for-next loops).