For i,v in pairs problem

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#1

The Problem
Hi there! I just made a system that flicker lights. All of the lights are stored in 1 folder and I got them from the folder using for i,v in pairs. The problem is that it doesn’t change all of the lights at the same time, but first one light and then another light, but not all of the lights on the same time.

The Code:
I used a localscript for this code.

-- Variables

local flickeringLights = game.Workspace:WaitForChild("FlickeringLights")

-- Core Script

while wait() do
		
	for i,v in pairs(flickeringLights:GetChildren()) do
				
		v.Light.Brightness = 10
				
		v.Material = Enum.Material.Neon
				
		wait(1)
				
		v.Light.Brightness = 0
				
		v.Material = Enum.Material.SmoothPlastic
				
		wait(0.3)
				
		v.Light.Brightness = 10
			
		v.Material = Enum.Material.Neon
				
		wait(0.5)
				
		v.Light.Brightness = 0
				
		v.Material = Enum.Material.SmoothPlastic
				
		wait(0.8)
		
	end
	
end

Thanks for reading and I hope you can help me :slightly_smiling_face:

1 Like
#2

Change WaitForChild() to FindFirstChild()

WaitForChild should be used to check if something has loaded not for variables :slight_smile:

1 Like
#3

Okay, thanks for the code tip! It only still doesn’t work.

#4

the pairs function has no specific order for iteration over associative tables, use ipairs for numerical indices and for guaranteed order.

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image1184×57 3.6 KB

(also faster and recommended in this case, no idea why pairs is being used)
you also added a wait() so the lights aren’t going to change state at the same time

3 Likes
#6

You are yielding in each iteration, so you have to wait to finish that to go onto the next iteration. Consider using coroutines:

Also you don’t need while wait() do.

while true do
	for i,v in pairs(flickeringLights:GetChildren()) do
		coroutine.wrap(function()
			v.Light.Brightness = 10
			v.Material = Enum.Material.Neon
			wait(1)
			v.Light.Brightness = 0
			v.Material = Enum.Material.SmoothPlastic
			wait(0.3)
			v.Light.Brightness = 10
			v.Material = Enum.Material.Neon
			wait(0.5)
			v.Light.Brightness = 0
			v.Material = Enum.Material.SmoothPlastic
			wait(0.8)
		end)()
	end
end
2 Likes
#7

Thanks! It worked! (btw, thanks to everyone that responded)

#8

That is because you have coded it to “wait” several times per every-single-light you iterate through. The same as incapaz points to, but then suggest a not-very-good alternative using coroutines (it would need at least a wait(1 + 0.3 + 0.5 + 0.8) per every while iteration.)

To “fix” that, you instead need to “wait” after the for-loop. So you would need to make multiple for-loops:

while true do

  -- Set all lights to brightness 10, material Neon
  for i,v in ipairs(flickeringLights:GetChildren()) do
    v.Light.Brightness = 10
    v.Material = Enum.Material.Neon
  end

  -- Wait one second
  wait(1)

  -- Set all lights to brightness zero, material SmoothPlastic
  for i,v in ipairs(flickeringLights:GetChildren()) do
    v.Light.Brightness = 0
    v.Material = Enum.Material.SmoothPlastic
  end

  -- Wait 0.3 second
  wait(0.3)

  -- etc.
end

As you probably don’t want to repeat all those for-loops again and again, then you can look into using functions with arguments:

local function SetAllLightsTo(brightness, material)
  -- Set all lights to the brightness and material, given as arguments to this function
  for i,v in ipairs(flickeringLights:GetChildren()) do
    v.Light.Brightness = brightness
    v.Material = material
  end
end

while true do

  SetAllLightsTo(10, Enum.Material.Neon)
  wait(1)

  SetAllLightsTo(0, Enum.Material.SmoothPlastic)
  wait(0.3)

  -- etc.
end
2 Likes
#9

This is probably going to cause a game script timeout