Accessing a variable from a string

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1

I was thinking about how javascript can access a variable within a string by doing

const var = 5
console.log(`String ${var} more String`) // "String 5 more String"

does lua have any similiar capability? Curious.

2

I’m not quite sure what you mean by that but you can use

modifiers to remove all the letters then all you have is a string full of numbers that can be converted to a number value since lua is a loose based coding language if i’m correct

though thats not good practice to get into and only works with those types of languages

3 
local var = 5
print(string.format("String %s more String",var)) -- String 5 more String

You mean something like this?

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4

I think I know what you mean. Is this what you’re looking for?

local var = 5
print("String "..var.." more String") -- "String 5 more String"
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5

it’s likely string interpolation will be coming to Luau in the future as there was a commit made awhile ago by KampfKarren to support *% specifier in anticipation for string interpolation which would truly implement what you mentioned.

string.format now supports %* in preparation for string interpolation support.

https://developer.roblox.com/en-us/resources/release-note/Release-Notes-for-539

In the meantime, you can use concatenation or string formatting to do it as other replies have mentioned.

local str = 'some string'

print('String ' .. str .. ' more String')
print(string.format('String %s more String', str)

Another thing to note is that Roblox’s print function allows for any type, including tables which IIRC using ${var} supports as well, so something like this would also work:

local t = {}
print('t is equal to', t)

If you want to get into the more advanced stuff, you can also use metatables using the __concat metamethod.

local t = {}

function t:__concat(value)
    return self.Name .. value
end

local myObj = {}
myObj.Name = 'super cool table'

setmetatable(myObj, t) print(myObj .. ' is cool') -- super cool table is cool

The print function also invokes the __tostring metamethod so if you want to return a property of the table like a name or class name, you can do that as well to make your print prettier.

local t = {}
function t:__tostring()
    return self.Name
end

local myObj = {}
myObj.Name = 'super cool table 2'
setmetatable(myObj, t)

print(myObj, 'is cool') --> super cool table 2 is cool
6

Yeah, I’m pretty sure this is the answer to @PerfectlySquared’s question. I don’t know why everyone is over complicating it.

7

Not over complicating it. Showing them more ways to do it so if they want to do it a different way.

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8

Doing metatables for concatenation is definitely overcomplicating it.

9

It’s called learning. I use a module I made specifically for concatenation, so I can do entire table in 1 string if i have too, etc.

10

string.format is actually the preferred method for this, though the other way works it has a lot of limitations and if you ever go to another language it will come back to bite you if you don’t spend a few seconds reading about string.format.

The one person who did that isn’t everyone and it was only an option of many.

11

Well, yeah. I was more talking about this:

local t = {}
function t:__tostring()
    return self.Name
end

local myObj = {}
myObj.Name = 'super cool table 2'
setmetatable(myObj, t)

print(myObj, 'is cool')
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