Pressing buttons in order to enable a line of code?

There are many different possible solutions for combination locks, and mine is only one of those many. While I do believe there are better solutions out there than mine, I'm pretty happy with what I have, and hopefully you are too.

String comparison

My combination lock involves comparing two string values (they could also be numbers, but I guess it doesn't really matter) after the length of the entry string is equal to the length of the combination string. Here's what I've come up with:

-- The combination of buttons pressed in order (each digit representing a button in that index)
local Combination = "2468"

-- entry records the characters the user inputs
-- buttons is an array of button objects
local entry = {}
local buttons = {}

-- You could insert them manually if you're in a more dynamic situation, or you could use GetChildren on the parent of all the buttons. It really depends, but index order matters.
buttons[1] = button1
buttons[2] = button2
buttons[3] = button3

-- Some constants for unnecessary optimization
local comboLen = #Combination 
local concat = table.concat

-- This function maps to each button's click event
local function buttonEvent(num)
    entry[#entry+1] = num -- New character entry

    -- Compare length of entry with combination length
    if #entry == comboLen then
        -- If it's equal, then compare their value and see if they're equivalent 
        if concat(entry) == Combination then
            -- If they are, the combination was completed in order
            print("Combination cracked")
        else
            -- If they're not, it wasn't.
            print("Invalid combination")
        end

        -- Clear the entry list
        for i = 1, comboLen do
            entry[i] = nil
        end
    end
end

-- Traverse the buttons, and connect our buttonEvent function to a click event
for i = 1, #buttons do
    local button = buttons[i] -- Individual button
    -- Use buttonEvent in a callback sort of way 
    button.MouseButton1Click:Connect(function()
        -- Notice how we're passing "i", the index to the function
        buttonEvent(i)
    end
end

It may seem a little complicated, but it's actually pretty simple. Each time we click the button, we push a new digit on the end of our entry table. We then check if both length and value are equal to the Combination to determine whether or not it's valid. In both cases, when the length of our entry is equal to the length of the combination, we reset the entry table because their combination was wrong.

Concatenation

In case you're wondering why I'm using table.concat instead of .. for concatenation, it's just a small optimization feature. Lua stores all created string values in memory which makes for quick retrieval, but somewhat slower construction. This way we're only creating strings 1-9, and just reusing what's in memory. If any of that doesn't make sense to you, you can just change it to .., it really doesn't matter in this situation.

Help & Questions

Just for fun, I made a quick implementation of the code above to prove it works, which you can check out here. If you have any further questions, just leave a comment and I'll get back to you as soon as possible.

Well since there is no code you could do something like 4 GUI buttons and inside of them add a bool value named code or something.

Then in your script just add checks with if statements. Say the click code is 1, 3, 2, 4. If button1 is clicked set code value to true because thats the first check in the code.

If button2 is clicked but button3's value isn't true then set all the values back to false because 3 is second number in the code, not 2.

Then keep checking until the player clicks 1 then 3 then 2 then 4 in order. Then have a check if all code values = true do something.

--Set up GUI vars

--Code = 1, 3, 2, 4

b1 = script.Parent.Button1  --Button1 
b2 = script.Parent.Button2 --Button2
b3 = script.Parent.Button3 --Button3
b4 = script.Parent.Button4 --Button4

code1 = b1.Code--Fist check
--[[
Rest of the checks
]]

b1.MouseButton1Click:Connect(function()
    code1.Value = true
end)

--b2 clicked
    if code1 == true and code 3 == true then
        code2.Value = true
    else
        code1.Value =  false
        --ect
        print("Pass reset")
    end

--b3 clicked
    if code1 == true then
        code3 = true
    end
--And so on

--You can make a for loop to check all of them
if they all == true then
    --unlock
end