INQ241B
Mobile Apps

Draw what the following script would draw when run:

action main()
  ◳angle := 0
  ▷go(25)
  ▷go(50)
end action

private action go(
  distance : Number)
do
  turtle→forward(distance * 2)
  ◳angle := ◳angle + 45
  turtle→left turn(◳angle)
end action

For the following script:

action main()
  var board := game→start
  var rectangle := create rectangle(100, 100)
  rectangle→set pos(rectangle→width / 2, board→height / 2)
  board→add on every frame(perform)
    where perform() is
      ▷update(rectangle)
  end
end action

private action update(
  sprite : Sprite)
do
  sprite→set x(sprite→x + 10)
  if sprite→right > board→width then
    sprite→set left(0)
  else do nothing end if
end action

1. Draw what will be displayed when the app first starts.

2. Describe what will happen when the app runs.

For the following script:

page main ()
initialize
  ◳count := 0
display
  boxed
    box→set width(10)
    box→set height(10)
    if ◳count = 0 then
      box→set background(colors→black)
    else
      box→set border(colors→black, 0.1)
    end if
    box→on tapped(handler)
      where handler() is
        ◳count := ◳count + 1
        if ◳count = 2 then
          ◳count := 0
        else do nothing end if
    end
  end boxed
end page

1. Draw what will be displayed when the app first starts.

2. Describe what will happen when the user presses the button multiple times.