Lua: Smartest way to add to table only if not already in table, or remove duplicates

Question

I have a table of strings. I\'d like an easy way to remove all of the duplicates of the table.

So if the table is {a, b, c, c, d, e, e} , after this ope

Answer 1

The simplest way is using the tables as keys, not as values, in your "container table".

Let's call the container table values. You must currently be doing something similar to this for adding elements to it:

table.insert(values, value)

And you parse values like this:

for i,v in ipairs(values) do
  -- v contains the internal values
end

In order to have the tables just once, you can insert them this other way:

t[value] = 1

This will ensure that the inserted values (strings, tables, numbers, whatever) are included just once, because they will be 'overwritten'.

Then you can parse t like this:

for k,_ in pairs(values) do
  -- k contains the internal tables
end