Preventing random number returning the same number twice

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#1

As the title suggests, how would I achieve this action? I cannot have the same number be used twice, or even more at the same time. Here’s the script:

for i,v in pairs(script.Parent:GetChildren()) do
	if v.Name == "t1" or v.Name == "t2" or v.Name == "t3" or v.Name == "t4" then
		if v:WaitForChild("IsCorrect").Value ~= true then
				v:WaitForChild("Number").Text = numbers[math.random(1,#numbers)]
-- Add something to prevent math.random() from creating the same number in one function call.
			end
		end
	end
1 Like
#2

You could store the result of each time in a table,
and then check if that number is there. If it is - dont let them get it.

#3

Sorry, but I would prefer to use a different method. Any ideas?

#4 
local generatedNumbers = {}

local function uniquePseudoRandomGenerator(lower : number, upper : number) : number
	if upper - lower + 1 == #generatedNumbers then return end
	local randomNumber
	repeat
		randomNumber = math.random(lower, upper)
	until not table.find(generatedNumbers, randomNumber)
	table.insert(generatedNumbers, randomNumber)
	return randomNumber
end

The return end statement is to prevent indefinite yielding.

3 Likes
How can I prevent getting the same number twice?
#5

You’re honestly the best @Forummer, you always solve my questions.

#6

Hey, this script works, but I can’t figure out how to work with my numberNames table. Heres the full script:

local numbers = {1,2,3,4,5,6,7,8,9,0}
local numberNames = {"One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Zero"}
local RandomButton = {1,2,3,4}
local generatedNumbers = {}
local QuestionLabel = script.Parent.QuestionLabel
local CorrectNum = script.Parent.CorrectNum
local t1 = script.Parent.t1
local t2 = script.Parent.t2
local t3 = script.Parent.t3
local t4 = script.Parent.t4
local QuestionLabelAnswer
local Correct

local function uniquePseudoRandomGenerator(lower : number, upper : number) : number
	if upper - lower + 1 == #generatedNumbers then print("err") end
	local randomNumber
	repeat
		randomNumber = math.random(lower, upper)
	until not table.find(generatedNumbers, randomNumber)
	table.insert(generatedNumbers, randomNumber)
	return randomNumber
end

local function RandomVerify()
	
	task.wait(0.42)
	
	CorrectNum.Value = uniquePseudoRandomGenerator(1,#numberNames) -- Need this to be a NumberName, but throws an error.
	QuestionLabel.Text = "Choose number: "..CorrectNum.Value

	if CorrectNum.Value == "One" then
		QuestionLabelAnswer = 1
	elseif CorrectNum.Value == "Two" then
		QuestionLabelAnswer = 2
	elseif CorrectNum.Value == "Three" then
		QuestionLabelAnswer = 3
	elseif CorrectNum.Value == "Four" then
		QuestionLabelAnswer = 4
	elseif CorrectNum.Value == "Five" then
		QuestionLabelAnswer = 5
	elseif CorrectNum.Value == "Six" then
		QuestionLabelAnswer = 6
	elseif CorrectNum.Value == "Seven" then
		QuestionLabelAnswer = 7
	elseif CorrectNum.Value == "Eight" then
		QuestionLabelAnswer = 8
	elseif CorrectNum.Value == "Nine" then
		QuestionLabelAnswer = 9
	elseif CorrectNum.Value == "Zero" then
		QuestionLabelAnswer = 0
	end

	Correct = RandomButton[math.random(1,#RandomButton)]

	if Correct == 1 then
		t1.IsCorrect.Value = true
		t1.Number.Text = QuestionLabelAnswer
	elseif Correct == 2 then
		t2.IsCorrect.Value = true
		t2.Number.Text = QuestionLabelAnswer
	elseif Correct == 3 then
		t3.IsCorrect.Value = true
		t3.Number.Text = QuestionLabelAnswer
	elseif Correct == 4 then
		t4.IsCorrect.Value = true
		t4.Number.Text = QuestionLabelAnswer
	end
for i,v in pairs(script.Parent:GetChildren()) do
	if v.Name == "t1" or v.Name == "t2" or v.Name == "t3" or v.Name == "t4" then
			if v:WaitForChild("IsCorrect").Value ~= true then
				v:WaitForChild("Number").Text = uniquePseudoRandomGenerator(1,#numbers)
			end
		end
	end
end



t1.MouseButton1Up:Connect(function()
	if t1.IsCorrect.Value == true then
		task.wait(1)
		t1.IsCorrect.Value = false
		RandomVerify()
	end
end)

t2.MouseButton1Up:Connect(function()
	if t2.IsCorrect.Value == true then
		task.wait(1)
		t2.IsCorrect.Value = false
		RandomVerify()
	end
end)

t3.MouseButton1Up:Connect(function()
	if t3.IsCorrect.Value == true then
		task.wait(1)
		t3.IsCorrect.Value = false
		RandomVerify()
	end
end)

t4.MouseButton1Up:Connect(function()
	if t4.IsCorrect.Value == true then
		task.wait(1)
		t4.IsCorrect.Value = false
		RandomVerify()
	end
end)

RandomVerify()
#7

Wait this doesnt make any sense. The first guy proposed an idea and you said you dont like this idea and then the other guy posts a script that does thr same thing as the first user described.

#8

Not being rude here, but I think he is too lazy to code it.