How to declare a "key" from a table to use another key from the same table?

[LOL08083]

You can write your topic however you want, but you need to answer these questions:

1. What do you want to achieve? Keep it simple and clear!
   I want to declare a “key” using another “key” from the same table
2. What is the issue? Include screenshots / videos if possible!
   I can’t declare a “key” table to use something from the same table
3. What solutions have you tried so far? Did you look for solutions on the Developer Hub?
   I tried this

local someTable = {
  ["Seconds"] = 120
  ["Minutes"] = self.Seconds/60
}

and this

local someTable = {
  ["Seconds"] = 120
  ["Minutes"] = someTable.Seconds/60
}

[steven4547466 (Steven)]

The only easy way I can think to do this is to define them out of the table:

local someTable = {}
someTable.Seconds = 120
someTable.Minutes = someTable.Seconds/60

You could use meta tables, but that’s just over engineering it.

[steven4547466 (Steven)]

This won’t work, firstly, this will say something along the lines of Attempt to index nil with seconds when you add the semi-colons, or commas at the end of the lines (otherwise it won’t run at all). And if you initialize someTable to {}, you’ll get Attempt to perform arithmetic on nil value.

You can see that here:

[Forummer]

local dictionary = {
	["Seconds"] = 120
}

local metadictionary = {
	["__index"] = function(dict, key)
		if key == "Minutes" then
			return dict["Seconds"]/60
		end
	end
}

setmetatable(dictionary, metadictionary)
print(dictionary["Minutes"]) --prints 2