--I set it like this:
DTClass = dataClass()
DTClass:addParam("var1Age", 10)
DTClass:addParam("var1Weight", 101)
DTClass:addParam("var2Age", 20)
DTClass:addParam("var2Weight", 102)
DTClass:addParam("var3Age", 30)
DTClass:addParam("var3Weight", 103)

--Then I have something like this:
DTClass = {
	var1Age = 10,
	var1Weight = 101,
	var2Age = 20,
	var2Weight = 102,
	var3Age = 30,
	var3Weight = 103
}

--The values are changeable in a interface

--I use it like this:
if DTClass.var1Age >= 21 then
	print(DTClass.var1Weight)
end