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What is string.sub and how do you use it? [closed]

Asked by

10 years ago

Hi, thank you for reading. After doing some digging and trying to understand it from wiki, I'm still confused. Why? On Wiki.Roblox, it said:

Returns the substring of s that starts at i and continues until j; i and j may be negative. If j is absent, then it is assumed to be equal to the length of s. In particular, the call string.sub(s,1,j) returns s until as many characters as j, and string.sub(s, -i) returns a suffix of s with length i.

This is a really weird description and if anyone can give me a simpler description, I would be really grateful.

~Thank you for reading, Yeevivor4

Locked by Zafirua, User#5423, and theCJarmy7

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1 answer

Answered by

EzraNehemiah_TF2 3552

10 years ago

string.sub, sub means substring or part-of-a-string. It's basically taking a string and cutting off a piece of it. e.g.

1print("Hello") --Hello
2 
3print("Hello", 2) --Ello

In string.sub it looks like something like this: string.sub("String", 2,4). string.sub is you know, string.sub. In the parentheses you have your string. "Hi", "Text", "string". Next you have a number. If it's just one number, that means anything before this number will be cut off. string. string.sub("String", 2) == "tring" --t is the 2nd number, 1 is before it so it gets cut off. If there is 2 numbers(you can only have 1 to 2 numbers) then it will cut off anything before the 1st number and anything past the 2nd number. string.sub("String", 2,4) == "tri" --ng and S get cut off. If you're wondering how do we know what numbers to use, lets say we have this weird string that has a message. "afakwshellosadffgafsadsadfge" we want it to say "hello". string.sub("afakwshellosadffgafsadsadfge", 6,11) --the 6th character in the string is "s". Everything before it(afakw) also get's deleted from the string. Now the 11th character is "s" again coincidentally. "s" and everything AFTER s is deleted(adffgafsadsadfge).

Hope it helps! If you're still having trouble understanding, please tell me!

Examples of string.sub in scripts:

Admin Scripts
Chat service

Admin

01admin = {"LordDragonZord"}
02 
03game.Players.PlayerAdded:connect(function(player)
04--  player.CharacterAdded:connect(function(char) --This isn't really necessary.
05        for _,name in pairs(admin) do
06            if player.Name == admin then
07                player.Chatted:connect(function(msg)
08                    if string.sub(msg, 1, 5) == "Kill/" and game.Players:FindFirstChild(string.sub(msg, 6)) then
09                        game.Players:FindFirstChild(string.sub(msg, 6)).Character.Humanoid.Health = 0
10                    end
11                end)
12            end
13        end
14--  end)
15end)

Chat

01local default_color = "Blue"
02 
03game.Players.PlayerAdded:connect(function(player)
04    player.Chatted:connect(function(msg)
05        if string.sub(msg, 1,2) == "R/" then
06            game:GetService("Chat"):Chat(player.Character.Head,string.sub(msg,3),"Red")
07        elseif string.sub(msg, 1,2) == "B/" then
08            game:GetService("Chat"):Chat(player.Character.Head,string.sub(msg,3),"Blue")
09        elseif string.sub(msg, 1,2) == "G/" then
10            game:GetService("Chat"):Chat(player.Character.Head,string.sub(msg,3),"Green")
11        else
12            game:GetService("Chat"):Chat(player.Character.Head,msg,default_color)
13        end
14    end)
15end)

Oh! That's super helpful! I was confused with chat function and you saying this plus showing the admin just helped me, even though I never had a question, lol alphawolvess 1784 — 10y

Why not use the 'string:sub(number,number)' method? In my opinion, it's easier, also a lot easier to read and write, but also reduces some-what code space. :) TheeDeathCaster 2368 — 10y

Okay :3 EzraNehemiah_TF2 3552 — 10y

You should edit this post with some bolding and some more paragraphs then lock it. This has a really clear concise answer that many people will find useful. DigitalVeer 1473 — 10y

@ DigitalVeer , this is too old anyway... EzraNehemiah_TF2 3552 — 10y