local mytable = {
"Yes",
"Hello",
"How do you do?",
"Hello",
"Yes",
"No"
}
This is just a very simplified version of what I have in my game. (I’m basically looping through recipes, adding all recipes matching the items given to a table like the one above, and then trying to remove repeating variables then output what you can craft with those items on a piece of paper (like Cube Combination) but I won’t get into it)
I’m wondering, as in the table above, I have 2 “Yes” and 2 “Hello” how do I refine the table so it ends up being this:
local mytable = {
"Yes",
"Hello",
"How do you do?",
"No"
}
I’m not sure, but… how are they getting in there in the first place? Maybe if you check if something is already there before you add it, then you wouldn’t need to remove it.
local _table = { "hi", "no", "hi", "hi" }
for index, item in _table do
local searchIndex = table.find(_table, item)
if searchIndex ~= index then
print("found duplicate")
table.remove(_table, searchIndex)
end
end
It only works for arrays, I can write another one for dictionaries if you want, and the only problem is that it only removes one, let me rewrite it, this is a better one. It’s O(n^2), but it should work for dictionaries, also.
local _table = { "hi", "no", "no", "hi", "hi" }
for index, item in _table do
for searchIndex, searchItem in _table do
if searchIndex == index then continue end
print("found duplicate")
table.remove(_table, searchIndex)
end
end
Since you don’t want elements to show up more than once in the collection, there’s a better type of collection that you can use: a set. A set is basically a collection where there aren’t repetitions. The usual way of making sets in Lua is like so:
local set = {} -- a new, empty set
set[someValue] = true -- adding a value to a set (any non-nil value could be used in place of true)
set[someValue] = true -- "adding" a value again doesn't change anything
set[someValue] = nil -- removing a value from a set
local isValueInSet = set[value] ~= nil --checking if a value is in a set
for value, _ in pairs(set) do -- Iterating over the set. pairs won't do as we're not working with an array-like table.
print(value)
end
Sets have some cool properties, like constant-time lookup and insertion in some cases. If you really want to find the unique values of a list instead, here’s an implementation that uses sets to make it faster for large input sizes:
function unique(list)
local seen = {}
for _, v in list do
seen[v] = true
end
local result = {}
for v, _ in seen do
table.insert(result, v)
end
return result
end
Removing halfway through the iteration might cause errors. Maybe make a duplicate, and you could use next or select to do things with that?
local myTable = {"Hello", "Hello", "Bye", "Good day"}
local clone = table.clone(myTable)
for key, value in next, myTable, nil do
local isClone = table.find(select(table.unpack(myTable), key))
if isClone then
table.remove(clone, isClone)
end
end
myTable = clone
local myTable = {"hello", "yes", "no", "idk", "hello", "yes"}
local function removeDuplicates(t)
local newTable = {}
for _, v in t do
if table.find(newTable, v) then continue end
table.insert(newTable, v)
end
return newTable
end
print(removeDuplicates(myTable))
This only applies to Python, another programming language. In lua, we don’t have sets. I know this as a professional python and lua scripter. Lua defines {} as tables (arrays and dictionaries are types of tables). You can’t automatically remove items in a ‘list’ (python terminology for table).
