Returning the index of a value in a Lua table

Question

I have this table in lua:

local values={"a", "b", "c"}

is there a way to return the index of the table if a variable equals one the table entries? say

local onevalue = "a"

how can I get the index of "a" or onevalue in the table without iterating all values?

Answer 1

There is no way to do that without iterating.

If you find yourself needing to do this frequently, consider building an inverse index:

local index={}
for k,v in pairs(values) do
   index[v]=k
end
return index["a"]