All questions/Question #20451

✓ ANSWER ACCEPTED

in pairs not working correctly?

Asked Jul 26, 2015554 views2 answers

The hierarchy goes like this. Workspace>Part>SurfaceGui>Frame> 10 Frames What the below script is suppose to do is change the BackgroundTransparency of all of the 10 frames at once, but instead, it changes the first frame visible/insivible and then the second and third and so on. I've used pairs for a long time so this is very frustrating for me. Your guys's help is always appreciated.

while wait(0) do 
	for _, v in pairs(workspace.Part.SurfaceGui.Frame:GetChildren()) do
		v.BackgroundTransparency = 1
		wait(2)
		v.BackgroundTransparency = 0
		wait(2)
	end
end

AnonymousJul 26, 2015Edited Jul 26, 2015

2 comments

Remove the last wait function.

AnonymousJul 26, 2015#

That makes no sense, all that does is make the next frame go visible and the last one go visible in a quicker manner. I need all of them to change at once.

AnonymousJul 26, 2015#

2 answers

✓ Accepted answer

A for loop works on each element. Your code says to do this:

Hide A
wait 2
Show A
wait 2
Hide B
wait 2
Show B
wait 2
....

It does what you wrote.

If you want to hide them all, wait 2, then show them all, then you should say that!:

while true do
	for _, v in pairs(workspace.Part.SurfaceGui.Frame:GetChildren()) do
		v.BackgroundTransparency = 1
	end
	wait(2)
	for _, v in pairs(workspace.Part.SurfaceGui.Frame:GetChildren()) do
		v.BackgroundTransparency = 0
	end
	wait(2)
end

A way to reduce the code-reuse and to let you do fancier things is to make a setTransparency function.

function setTransparency(t)
	for _, v in pairs(workspace.Part.SurfaceGui.Frame:GetChildren()) do
		v.BackgroundTransparency = t
	end
end

Your loop then simply becomes

while true do
	setTransparency(0)
	wait(2)
	setTransparency(1)
	wait(2)
end

It's now even easier to do things like fading:

while true do
	for t = 0, 1, 0.03 do
		wait()
		setTransparency(t)
	end
end

Coroutines are not the solution to this. They consume many resources. Coroutines are designed to compute things cooperatively. They are not designed to do two things at the same time. They make code much harder to understand, debug, and write. Don't use coroutines.

if you insist on creating coroutines to do things in parallel, you should use spawn so that your intent is clear. Coroutines are very powerful, and if you're just creating new ones to do things in the background, you might as well save some typing as use spawn.

Two Previous Answers that discuss doing multiple things at once

AnonymousJul 26, 2015Edited Jul 26, 2015Permalink

That's because you're yielding in the for loop, which means it won't move on to the next task until the for loop is complete. You can avoid this problem by using a coroutine, which makes a new thread to execute the for loop in so it can resume iterating through all the frames and assign them all a function at the same time (like giving them all an invisible script).

Try and study this:

while wait() do
	for _,v in pairs (workspace.Part.SurfaceGui.Frame:GetChildren()) do
		coroutine.resume(coroutine.create(function()
			v.BackgroundTransparency = 1
			wait(2)
			v.BackgroundTransparency = 0
			wait(2)
		end))
	end
end

'coroutine' is a table consisting of many different functions to manipulate what a coroutine does. I don't wanna go into specific detail about how these functions work, but i recommend you study the ROBLOX wiki on them. Hope this helped!

AnonymousJul 26, 2015Edited Jul 26, 2015Permalink

1 comment

Coroutines are bad -- this is not what coroutines are for. There's also no guarantee that all of the objects will by in-sync if you do this, and if there's many frames, it's very likely they won't be. It also will consume significantly more resources and let you do much less elsewhere.

AnonymousJul 26, 2015#

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