How can i keep this table in the shown order? - lua

Hello i have got a table, that uses string indexes:
shirt = {
["shirtwhite.png"] = "shirt_white.png",
["shirtwhite.png^[multiply:#3f3f3f"] = "shirt_white.png^[multiply:#3f3f3f",
["shirtwhite.png^[multiply:#ff0000"] = "shirt_white.png^[multiply:#ff0000",
["shirtwhite.png^[multiply:#ff7f00"] = "shirt_white.png^[multiply:#ff7f00",
["shirtwhite.png^[multiply:#ffff00"] = "shirt_white.png^[multiply:#ffff00",
["shirtwhite.png^[multiply:#00ff00"] = "shirt_white.png^[multiply:#00ff00",
["shirtwhite.png^[multiply:#0000ff"] = "shirt_white.png^[multiply:#0000ff",
["shirtwhite.png^[multiply:#9f00ff"] = "shirt_white.png^[multiply:#9f00ff",
},
Theese are t-shirt-textures for an editable game-character-skin (with colour-values for different colors).
There are some more of theese tables in the code, for other parts of the character-skin
how can I keep the table in it´s shown order, while it´s loaded in this code-snippet?
The tzables are in a file "skins.lua" and the code-snippet is from another lua-file
character_creator = {}
character_creator.skins = dofile(minetest.get_modpath("character_creator") .. "/skins.lua")
local skins = character_creator.skins
local skins_array = {}
minetest.after(0, function()
local function associative_to_array(associative)
local array = {}
for key in pairs(associative) do
table.insert(array, key)
end
return array
end
skins_array = {
skin = associative_to_array(skins.skin),
hair = associative_to_array(skins.hair),
eyes = associative_to_array(skins.eyes),
shirt = associative_to_array(skins.shirt),
pants = associative_to_array(skins.pants),
}
end)

In Lua only arrays (positive integer-indexed tables) have "order" (can be iterated using ipairs); the hash tables (like the one you are working with) are unordered. If you want to iterate over a table like this in a specific order, you'd usually create an array with the keys, sorted them in the order you want and then iterate over that array extracting elements from your table.
There are also components (like ordered table) that may keep track of insertions and return results in the same order, if that's what you want.

Related

table.insert adding a unknown table

So im trying to add a table inside another table but each time i do it, it adds a "1": from nowhere...
my code :
local previousClothes = json.decode(xPlayer.get('clothes'))
print("old previousClothes"..json.encode(previousClothes))
local clothes = {[label] = {[parentName] = parentValue, [partName] = partValue}}
print("old clothes"..json.encode(clothes))
clothes[#clothes+1] = previousClothes
print("new clothes: "..json.encode(clothes))
xPlayer.get('clothes') = my clothes stored in my db
local clothes = my new clothes received in the function/event
and here comes my issue.. it adds a "1": to my table
https://i.stack.imgur.com/sb5pj.png
Instead of adding previousClothes as an array element to clothes, you can copy key-value pairs of previousClothes into clothes.
for k, v in pairs(previousClothes) do
clothes[k] = v
end
I assume this is what you want.
Because Your clothes is not an array, see the documentation in here. When you use # get a table length, it is better to be an array.

Obtain values from embedded tables Lua

I am new to Lua and I am trying to learn how to make a function with embedded tables. I am stuck trying to figure out a way to make the function meet specific values in the table.
Here is an example of a table:
TestTable = {destGUID1 = {catagory1 = {A=1,B=5,C=3},catagory2 = {A=5,B=3,C=2}},destGUID2 = {catagory1 = {A=1,B=5,C=3},catagory2 = {A=5,B=3,C=2}}}
Now I want to make a function for this table that pulls values only from the specific destGUID. Like:
function CatInfo(GUID,Cat)
for i=1, #TestTable do
if TestTable[i] == GUID then
for j=1, TestTable[i][GUID] do
if TestTable[i][GUID][j] == Cat then
return TestTable[i][GUID][Cat].A -- returns value "A"
end
end
end
end
end
So that when I use this function, I can do something like this:
CatInfo(destGUID2,catagory1) -- returns "1"
Given your table structure, you don't need to do any looping; you can simply return the value from the table based on GUID and the category:
TestTable = {
destGUID1 = {catagory1 = {A=1,B=5,C=3},catagory2 = {A=5,B=3,C=2}},
destGUID2 = {catagory1 = {A=1,B=5,C=3},catagory2 = {A=5,B=3,C=2}}
}
function CatInfo(GUID,Cat)
return TestTable[GUID][Cat].A
end
print(CatInfo('destGUID2','catagory1'))
This will print 1. Note that destGUID2 and catagory1 need to be in quotes as those are strings.

lua: user input to reference table

I am having trouble with my tables, I am making a text adventure in lua
local locxy = {}
locxy[1] = {}
locxy[1][1] = {}
locxy[1][1]["locdesc"] = "dungeon cell"
locxy[1][1]["items"] = {"nothing"}
locxy[1][1]["monsters"] = {monster1}
The [1][1] refers to x,y coordinates and using a move command I can successfully move into different rooms and receive the description of said room.
Items and monsters are nested tables since multiple items can be held there (each with their own properties).
The problem I am having is getting the items/monsters part to work. I have a separate table such as:
local monsters = {}
monsters["rat"] = {}
monsters["rat"]["Name"] = "a rat"
monsters["rat"]["Health"] = 5
monsters["rat"]["Attack"] = 1
I am using a table like this to create outlines for various enemy types. The monster1 is a variable I can insert into the location table to call upon one of these outlines, however I don't know how to reference it.
print("You are in ", locxy[x][y]["locdesc"]) -- this works
print("You can see a ", locxy[x][y]["monsters]["Name"],".") - does not work
So I would like to know how I can get that to work, I may need a different approach which is fine since I am learning. But I would also specifically like to know how to / if it possible to use a variable within a table entry that points to data in a separate table.
Thanks for any help that can be offered!
This line
locxy[x][y]["monsters]["Name"]
says
look in the locxy table for the x field
then look in the y field of that value
look in the "monsters"` field of that value
then look in the "Name" field of that value
The problem is that the table you get back from locxy[x][y]["monsters"] doesn't have a "Name" field. It has some number of entries in numerical indices.
locxy[x][y]["monsters][1]["Name"] will get you the name of the first monster in that table but you will need to loop over the monsters table to get all of them.
Style notes:
Instead of:
tab = {}
tab[1] = {}
tab[1][1] = {}
you can just use:
tab = {
[1] = {
{}
}
}
and instead of:
monsters = {}
monsters["rat"] = {}
monsters["rat"]["Name"] = "foo"
you can just use:
monsters = {
rat = {
Name = "foo"
}
}
Or ["rat"] and ["Name"] if you want to be explicit in your keys.
Similarly instead of monsters["rat"]["Name"] you can use monsters.rat.Name.

Create a numerical table from the values of a non numerical table

Backpack = {Potion = 'backpack',Stack = 'bag',Loot = 'derp', Gold = 'random'}
Backpack[1] ~= 'backpack' -- nope
As you guys can see, I cannot call Backpack[1] since its not a numeral table, how would I generate a table after the construction of Backpack, consisting only of it's values? for example:
Table_to_be_Constructed = {Value of Potion,Value of Stack,Value of Loot,Value of Gold} -- this is what i need
It seems simple but I couldn't find a way to do it.
I need it this way because i will run a numeric loop on Table_to_be_Constructed[i]
To iterate over all the key-value pairs in a table, use the pairs function:
local Table_to_be_Constructed = {}
for key, value in pairs(Backpack) do
table.insert(Table_to_be_Constructed, value)
end
Note: the iteration order is not defined. So, you might want to sort Table_to_be_Constructed afterwards.
By convention, the variable name _ is used to indicate a variable who's value won't be used. So, since you want only the values in the tables, you might write the loop this way instead:
for _, value in pairs(Backpack) do
For the updated question
Backpack has no order (The order in the constructor statement is not preserved.) If you want to add an order to its values when constructing Table_to_be_Constructed, you can do it directly like this:
local Table_to_be_Constructed = {
Backpack.Potion,
Backpack.Stack,
Backpack.Loot,
Backpack.Gold
}
Or indirectly like this:
local items = { 'Potion', 'Stack', 'Loot', 'Gold' }
local Table_to_be_Constructed = {}
for i=1, #items do
Table_to_be_Constructed[i] = Backpack[items[i]]
end

How to quickly initialise an associative table in Lua?

In Lua, you can create a table the following way :
local t = { 1, 2, 3, 4, 5 }
However, I want to create an associative table, I have to do it the following way :
local t = {}
t['foo'] = 1
t['bar'] = 2
The following gives an error :
local t = { 'foo' = 1, 'bar' = 2 }
Is there a way to do it similarly to my first code snippet ?
The correct way to write this is either
local t = { foo = 1, bar = 2}
Or, if the keys in your table are not legal identifiers:
local t = { ["one key"] = 1, ["another key"] = 2}
i belive it works a bit better and understandable if you look at it like this
local tablename = {["key"]="value",
["key1"]="value",
...}
finding a result with : tablename.key=value
Tables as dictionaries
Tables can also be used to store information which is not indexed
numerically, or sequentially, as with arrays. These storage types are
sometimes called dictionaries, associative arrays, hashes, or mapping
types. We'll use the term dictionary where an element pair has a key
and a value. The key is used to set and retrieve a value associated
with it. Note that just like arrays we can use the table[key] = value
format to insert elements into the table. A key need not be a number,
it can be a string, or for that matter, nearly any other Lua object
(except for nil or 0/0). Let's construct a table with some key-value
pairs in it:
> t = { apple="green", orange="orange", banana="yellow" }
> for k,v in pairs(t) do print(k,v) end
apple green
orange orange
banana yellow
from : http://lua-users.org/wiki/TablesTutorial
To initialize associative array which has string keys matched by string values, you should use
local petFamilies = {["Bat"]="Cunning",["Bear"]="Tenacity"};
but not
local petFamilies = {["Bat"]=["Cunning"],["Bear"]=["Tenacity"]};

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