loop within a loop

[iluvchairs112]

how does a loop within a loop work?

loop % start first loop

redx:=redx+10 %redx increases by 10
delay(50)
redy:=redy+10 %redy increases by 10
delay(50)

if redx=300
then
loop
redx:=redx-10
delay(50)
redy:=redy-10
delay(50)
end loop
end if

drawfilloval(redx, redy, redxr, redyr, 40)
drawfilloval(orangex, orangey, orangexr, orangeyr, 65)

end loop


basically what I want to happen is the red circle goes up until it reaches a certain point(when x=300) and then have it go back down again
it should be simple, but my code just stops it ... it doesn't continue back down
what am I missing?

[Clayton]

Well, what does redx start off as? Once it enters that if statement, and that nested loop, it never gets out, because there is no exit condition.

[BenLi]

a couple of issues, in order to see it, the drawoval needs to be in the nested loop as well. Even then, you won't see a difference because its going down the way it went up. Perhaps you meant something like this?

code:

var redx, redy := 0 loop % start first loop     redx := redx + 10 %redx increases by 10     delay (50)     redy := redy + 10 %redy increases by 10     delay (50)     if redx = 300             then         loop             redx := redx + 10             delay (50)             redy := redy - 10             delay (50)             drawfilloval (redx, redy, 10, 10, 40)         end loop     end if     drawfilloval (redx, redy, 10, 10, 40) end loop

However, a nested loops is not the best solution for your problem, consider something like this, where the y value increments by a negative or a positive value

code:

setscreen ("graphics:max,max") var redx, redy := 0 var n := 10 loop % start first loop     if redy < 0 then         n := 10     elsif redy > 300 then         n := -10     end if     redx := redx + 10     redy := redy + n     drawfilloval (redx, redy, 10, 10, 40)     delay (10) end loop

Quote:

Well, what does redx start off as? Once it enters that if statement, and that nested loop, it never gets out, because there is no exit condition.

Good point, however, if he only wants to animate one time, he doesn't need to, however, its bad to have an infinite loop none the less