How do I keep only uppercase letters in a string

[BloxyCola_Gamer (Bloxy)]

How would I remove every character from a string that is not a capital character using code?

(“Hello World”) > (“HW”)

[FroDev1002 (FroDev)]

Not sure if this is the best way, but it works:

local function GetUpperCase(Text:string)
    local Uppercase = {}

    for index, Character:string in pairs(string.split(Text,'')) do
        if string.upper(Character) == Character then
            Uppercase[index] = Character
        end
    end

    return table.concat(Uppercase,''), Uppercase
end

This function should return a string that contains all the uppercase characters, and then an array of the characters

local OnlyUppercase:string, ListOfCharacters = GetUpperCase('Frodev is SO cool')
print(OnlyUppercase) -> "FSO"

[The_IntoDev]

Hey there! String functions can save your day! They are highly optimized, so usually you shall seek for a string function that works!

string.gsub("Hello World!", "[%l%d%p ]", "")

The code above will return HW

string.gsub("Goodbye World!", "[%l%d%p ]", "")

The code above will return GW

If you’re wondering how it works, I’m simply using the string gsub function, which replaces certain parts of a string with whatever you’d like. I simply make it find spaces, lowecase letters and other special symbols like ! and have it replace it with an empty string: "".

If you’d like further understanding of string patterns for future use, Roblox has an official documentation here.

[FroDev1002 (FroDev)]

I knew there was someway to go about using gsub and formatting, I just havent figured it out lol.
On the subject of this, what are all the formatting options? There are so many I cant keep up with it.

Def use this over my reply, its much better.

[BloxyCola_Gamer (Bloxy)]

@FroDev1002

local function GetUpperCase(Text:string)
    local Uppercase = {}

    for index, Character:string in pairs(string.split(Text,'')) do
        if string.upper(Character) == Character then
            Uppercase[index] = Character
        end
    end

    return table.concat(Uppercase,''), Uppercase
end

thank you for the quick reply!

[The_IntoDev]

As I mentioned in my now edited message, Roblox has a documentation on most of it here.
I’d recommend going through the full String Pattern Reference section for a full understanding of it.

[FroDev1002 (FroDev)]

Ok cool, thanks!