Bizzare "Attempt to Call a Table Value" in Lua
The Following Code Snippet: for Weight, Item in Itemlist Do Weight_Total=Weight_Total+Weight End Is Causing the Error "Attempt to Call Table Value" on the...
The following code snippet:
for weight, item in itemlist do
weight_total=weight_total+weight
end
is causing the error "attempt to call table value" on the first line in that snippet. Why?
Itemlist is a table of tables of weights and strings, like such:
local itemlist = {
{4,"weapon_pistol"},
{2,"weapon_357"},
...
Nothing is being called as far as I can tell; why is this error coming up?
1 Answer
The generic for expects 3 arguments: a callable value, some value which is repeatedly passed to it, and the key where the iteration shall start.
Stock lua does not call pairs on the first value passed to for if that's not callable, though some derivatives do.
Thus, you must use ipairs(itemlist), pairs(itemlist), next, itemlist or whatever you want (the last two have identical behavior, and are what most derivatives do).
As an example, an iterator unpacking the value sequence:
function awesome_next(t, k)
k, t = next(t, k)
if not t then return end
return k, table.unpack(t)
end
for k, a, b, c, d in awesome_next, t do
end
Maya is a hardware enthusiast who tests and reviews smart home devices, smartphones, wearables, and audio gear. She focuses on practical consumer value and build quality.
