How to Dissect Numbers From Strings?

So what I do here its creating function named what you want you can change that if you want but don't forgot to change the name when you calling your function too. Assert check if the type of the parametre taken is a string, after we're creating 2 table, 1 to got all of characters in the string and the other for returning the numbers.After, yeah after again, we're now taking all of letter in the text and insert it in the table named as > "String"> , then we're looking in the letter if the letter is a number and insert it in the table named as >"number"> else it does nothing.Finally we returning the table >number> and we're getting all numbers.

function findNumbersInString(text)
    assert(type(text) == "string", "The parametre given should be a string !")
    local String, number = {}, {};
    local position = 0;
    for i = 1, #text do
        String[i] = string.sub(text, i, i);
    end
    for i = 1, #text do
        if tonumber(String[i]) then
            table.insert(number, position + 1, String[i])
            position = position + 1
        end
    end
    return table.concat(number, '')
end

local txt = "Hello152"
print(findNumbersInString(txt))

First of all, you would need to create a function that returns the numbers of this, which i assume you'd already known.

Anyways, let's get straight to the code. To do this, we'll need to set up a table of numbers, and we'll pick through the word to remove the letters. Try this:

function numbersof(Text)
    local Digits={"0","1","2","3","4","5","6","7","8","9"}
    local NumbersInText="" --Sets up string to return
    for i=1,Text:len() do
        local Valid=false --Sets up variable to decide if to keep the substring
        for _,Digit in pairs(Digits) do
            if Text:sub(i,i)==Digit then --Checks if the substring is a digit
                Valid=true
            end
        end
        if Valid==true then
            NumbersInText=NumbersInText..Text:sub(i,i) --Adds to total string to return
        end
    end
    return NumbersInText
end

Word = "ROBLOX122"
print(numbersof(Word))

Anyways, I hope this makes sense. I've tested it out and it works fine for me.

If you have any further questions/problems then please leave a comment below. Hope I helped :P

-Dyler3

Based on the comments below (thanks so much for them, by the way!), I've decided to fix my answer;

example = "3Roblox122" -- Your string.
pattern = "%d+" Finds numerics in string

AllNumbers = {} -- Creates a table for you to store all of the numbers in

for match in example:gmatch(pattern) do -- Finds all matches in the pattern "%d+"
    table.insert(AllNumbers, #AllNumbers+1, match) -- Inserts these values into a table
end

print(table.concat(AllNumbers, "")) -- prints them all out side-by-side and in order.

Again, thanks so much for helping me fix this answer :).