How to fix "attempt to concatenate table and string"? - lua

I asked a question similar to this the other day, but another bug popped up "attempt to concatenate table and string"
local questions={
EN={
Q2={"Who is the lead developer of Transformice?","Tigrounette"},
Q4={"What is Eminem's most viewed song on youtube?","I love the way you lie"},
Q6={"What is the cubic root of 27?","3"},
Q8={"What are the first 3 digits of Pi","3.141"},
Q10={"What is the most populated country?","China"},
Q12={"What is the plural of the word 'Person'?","People"},
Q14={"Entomology is the science that studies ...?","Insects"},
Q16={"Who was the creator of the (bot ran) minigame fight?","Cptp"},
Q18={"The ozone layer restricts ... radiation","Ultraviolet"},
Q20={"Filaria is caused by ...","Mosquitos"}
}
local main = questions.EN["Q"..math.random(1,20)].."%s" -- bug here
local current_answer_en = string.gsub(current_question_en,1,2)

What type of object is questions.EN["Q"..math.random(1,20)]? Say random is 15, what type of object is questions.EN["Q6"]? It is a {"What is the cubic root of 27?","3"}, which is a table, which Lua doesn't know how to concatenate with a string ("%s" in your case). If you want to concatenate with the first item of this table, then
local main = questions.EN["Q"..math.random(1,20)][1] .. "%s"
Note however that you will need the "random with step" function that I posted in math.random function with step option?, otherwise you could get that the table EN["Q"..something] is nil (if the random number is an odd number, in the code you posted).
Note sure what you are trying to do with current_question_en but if you are trying to extract the question and answer you could do something like this:
local QA = questions.EN["Q"..math.random(1,20)] -- this is a table
local question, answer = QA[1], QA[2]
The other option is that you build your table like this:
local questions={
EN={
Q2={q="Who is ..?", a="Tigrounette"},
Q4={q="What is ...?", a="I love the way you lie"},
...
}
}
Then you could use
local QA = questions.EN["Q"..math.random(1,20)] -- this is a table
print("The question:", QA.q)
print("The answer:", QA.a)
Not sure what you're trying to do with string.gsub but it does not take integers as 2nd and 3rd args.

Related

I am looking for a Lua find and replace logic

enter image description here
I just started working on lua scripting since a week. I have a lua file where in the logic needs to be written for a certain condition.
The condition when gets triggered
it does an iteration on one of the fields to change value from
(ABC123-XYZ) to this value
(ABC123#1-XYZ) and it keeps increasing whenever iterations happens (ABC123#2-XYZ)
I need to run a function that removes the # followed by number to change it back to (ABC123-XYZ). Looking for any advice!
Edit 1:
Below is the updated code that is written Thanks to #Piglet
I have another scenario if therr are two hashes in the variable.
local x = 'BUS144611111-PNB_00#80901#1555-122TRNHUBUS'
local b = x:gsub("#%d+","")
function remove_char(a) a=a:gsub("#%d+","")
return a;
end if string.match(x,"#")
then print('function')
print(remove_char(x));
else print(x);
end
Expected output should be
x = 'BUS144611111-PNB_00#80901-122TRNHUBUS' for the aforesaid variable
local a = "ABC123#1-XYZ"
local b = a:gsub("#%d+", "")
this will remove any # followed by or one more digits from your string.

Issue returning desired data with Lua

Wondering if I could get some help with this:
function setupRound()
local gameModes = {'mode 1','mode 2','mode 3'} -- Game modes
local maps = {'map1','map2','map3'}
--local newMap = maps[math.random(1,#maps)]
local mapData = {maps[math.random(#maps)],gameModes[math.random(#gameModes)]}
local mapData = mapData
return mapData
end
a = setupRound()
print(a[1],a[2]) --Fix from Egor
What the problem is:
`
When trying to get the info from setupRound() I get table: 0x18b7b20
How I am trying to get mapData:
a = setupRound()
print(a)
Edit:
Output Issues
With the current script I will always the the following output: map3 mode 2.
What is the cause of this?
Efficiency; is this the best way to do it?
While this really isn't a question, I just wanted to know if this method that I am using is truly the most efficient way of doing this.
First of all
this line does nothing useful and can be removed (it does something, just not something you'd want)
local mapData = mapData
Output Issues
The problem is math.random. Write a script that's just print(math.random(1,100)) and run it 100 times. It will print the same number each time. This is because Lua, by default, does not set its random seed on startup. The easiest way is to call math.randomseed(os.time()) at the beginning of your program.
Efficiency; is this the best way to do it?
Depends. For what you seem to want, yes, it's definitely efficient enough. If anything, I'd change it to the following to avoid magic numbers which will make it harder to understand the code in the future.
--- etc.
local mapData = {
map = maps[math.random(#maps)],
mode = gameModes[math.random(#gameModes)]
}
-- etc.
print(a.map, a.mode)
And remember:
Premature optimization is the root of all evil.
— Donald Knuth
You did very good by creating a separate function for generating your modes and maps. This separates code and is modular and neat.
Now, you have your game modes in a table modes = {} (=which is basically a list of strings).
And you have your maps in another table maps = {}.
Each of the table items has a key, that, when omitted, becomes a number counted upwards. In your case, there are 3 items in modes and 3 items in maps, so keys would be 1, 2, 3. The key is used to grab a certain item in that table (=list). E.g. maps[2] would grab the second item in the maps table, whose value is map 2. Same applies to the modes table. Hence your output you asked about.
To get a random game mode, you just call math.random(#mode). math.random can accept up to two parameters. With these you define your range, to pick the random number from. You can also pass a single parameter, then Lua assumes to you want to start at 1. So math.random(3) becomes actually math.random(1, 3). #mode in this case stand for "count all game modes in that table and give me that count" which is 3.
To return your chosen map and game mode from that function we could use another table, just to hold both values. This time however the table would have different keys to access the values inside it; namely "map" and "mode".
Complete example would be:
local function setupRound()
local modes = {"mode 1", "mode 2", "mode 3"} -- different game modes
local maps = {"map 1", "map 2", "map 3"} -- different maps
return {map = maps[math.random(#maps)], mode = modes[math.random(#modes)]}
end
for i = 1, 10 do
local freshRound = setupRound()
print(freshRound.map, freshRound.mode)
end

splitting lua strings into variables

I am pretty new to this, so I hope you can give me a hand.
I am programming lights, and what I like to do is take a variable from my lighting desk (a text string called "4 Mythos Stage") and split is into different variables.
to get the variables from the desk I use:
return function ()
local Layer1 = gma.user.getvar("Layer1") -- I placed "4 Mythos Stage" variable in Layer1
gma.feedback(Layer1) -- gives feedback 4 Mythos Stage
end
Now I would like to split the string into 3 new local variables named:
local number -- should produce 4
local fixturetype -- should produce Mythos
local location -- should produce Stage
i tried the following:
local number = string.match('Layer1', '%d+')
local fixturetype = string.match('Layer1', '%a+')
local location = string.match('Layer1', '%a+')
this didn't work, so can somebody please help me in the right direction. I would be really greatful.
with kind regards,
Martijn
You can assign all three variables at the same time, because Lua has multiple returns and multiple assignment. Put parentheses around each of your patterns in order to return them as captures, and combine them into a single pattern with spaces between them:
local number, fixturetype, location = string.match(Layer1, '(%d+) (%a+) (%a+)')
In case you will be using multiple spaces or tabs between the items, this pattern would be better:
local number, fixturetype, location = string.match(Layer1, '(%d+)[ \t]+(%a+)[ \t]+(%a+)')
The reason why your attempt didn't work is because string.match('Layer1', '%d+') is searching inside 'Layer1' (a string) instead of Layer1 (a variable).
But even if you corrected that, you would get 'Mythos' every time you called string.match(Layer1, '%a+') (where Layer1 == '4 Mythos Stage'). string.match always starts from the beginning of the string, unless you supply an index in the third parameter: string.match(Layer1, '%a+', 9) --> 'Stage'.
A robust solution for this task is to split the string into three "words", a word being a sequence of non-whitespace characters:
local number, fixturetype, location = string.match(Layer1, '(%S+)%s+(%S+)%s+(%S+)')

Elder Scroll Online Addon

This is my first time working with Lua, but not with programming. I have experience in Java, Action Script, and HTML. I am trying to create an addon for Elder Scroll Online. I managed to find the ESO API at the following link:
http://wiki.esoui.com/API#Player_Escorting
I am trying to make a function that returns a count of how many items each guild member has deposited in the bank. The code I have so far is as follows
function members()
for i=0, GetNumGuildEvents(3, GUILD_EVENT_BANKITEM_ADDED)
do
GetGuildEventInfo(3, GUILD_EVENT_BANKITEM_ADDED, i)
end
I am having trouble referencing the character making the specific deposit. Once I am able to do that I foresee making a linked list storing character names and an integer/double counter for the number of items deposited. If anyone has an idea of how to reference the character for a given deposit it would be much appreciated.
I don't have the game to test and the API documentation is sparse, so what follows are educated guesses/tips/hints (I know Lua well and programmed WoW for years).
Lua supports multiple assignment and functions can return multiple values:
function foo()
return 1, "two", print
end
local a, b, c = foo()
c(a,b) -- output: 1, "two"
GetGuildEventInfo says it returns the following:
eventType, secsSinceEvent, param1, param2, param3, param4, param5
Given that this function applies to multiple guild event types, I would expect param1 through param5 are specific to the particular event you're querying. Just print them out and see what you get. If you have a print function available that works something like Lua's standard print function (i.e. accepts multiple arguments and prints them all), you can simple write:
print(GetGuildEventInfo(3,GUILD_EVENT_BANKITEM_ADDED,i))
To print all its return values.
If you don't have a print, you should write one. I see the function LogChatText which looks suspiciously like something that would write text to your chat window. If so, you can write a Lua-esque print function like this:
function print(...)
LogChatText(table.concat({...}, ' '))
end
If you find from your experimentation that, say, param1 is the name of the player making the deposit, you can write:
local eventType, secsSinceEvent, playerName = GetGuildEventInfo(3,GUILD_EVENT_BANKITEM_ADDED, i)
I foresee making a linked list storing character names and an integer/double counter for the number of items deposited.
You wouldn't want to do that with a linked list (not in Lua, Java nor ActionScript). Lua is practically built on hashtables (aka 'tables'), which in Lua are very powerful and generalized, capable of using any type as either key or value.
local playerEvents = {} -- this creates a table
playerEvents["The Dude"] = 0 -- this associates the string "The Dude" with the value 0
print(playerEvents["The Dude"]) -- retrieve the value associated with the string "The Dude"
playerEvents["The Dude"] = playerEvents["The Dude"] + 1 -- this adds 1 to whatever was previous associated with The Dude
If you index a table with a key which hasn't been written to, you'll get back nil. You can use this to determine if you've created an entry for a player yet.
We're going to pretend that param1 contains the player name. Fix this when you find out where it's actually located:
local itemsAdded = {}
function members()
for i=0, GetNumGuildEvents(3, GUILD_EVENT_BANKITEM_ADDED ) do
local eventType, secsSinceEvent, playerName = GetGuildEventInfo(3, GUILD_EVENT_BANKITEM_ADDED, i)
itemsAdded[playerName] = (itemsAdded[playerName] or 0) + 1
end
end
itemsAdded now contains the number of items added by each player. To print them out:
for name, count in pairs(itemsAdded) do
print(string.format("Player %s has added %d items to the bank.", name, count))
end

Variable names in table field not working

I came across a problem while writing some code up for a game. It seems I can't use variables in statements like;
local Username = "Cranavvo"
game.Players.Username:BreakJoints() -- Kills the player
And the output is telling me "No such user as 'Username'" which should be "Cranavvo".
From Lua PiL on tables
To represent records, you use the field name as an index. Lua supports
this representation by providing a.name as syntactic sugar for
a["name"].
A common mistake for beginners is to confuse a.x with a[x]. The first
form represents a["x"], that is, a table indexed by the string "x".
Therefore, when you try:
game.Players.Username:BreakJoints()
Lua interprets it as:
game["Players"]["Username"]:BreakJoints()
which ofcourse is wrong. If you want to use varying name as index for a table, use them like this:
local foo = "Cranavvo"
game.Players[foo]:BreakJoints()
But to be mentioned is that the Player class do not have a BreakJoints method, you have to get the character model with help of the .Character attribute like this:
local foo = "Cranavvo"
game.Players[foo].Character:BreakJoints()
Also to be mentioned is that if the player with that name does not exist the code will break, and also that the character can be null, in which case it also breaks. Thus you need to add some error handling. Like this:
local foo = "Cranavvo"
local Player = game.Players:findFirstChild(foo)
if Player ~= nil and Player.Character ~= nil then
Player.Character:BreakJoints()
end
The correct way to do this in roblox is this:
local Username = "Cranavvo"
local p = game.Players:FindFirstChild(Username)
if(p ~= nil) then
if(p.Character ~= nil) then
p.Character:BreakJoints()
end
end
Double check if the user really exists at the time your code gets executed.
Also it should be:
game.Players.Username:BreakJoints()
EDIT:
I misread what you wanted to do:
in
...Players.Username
lua interprets Username as a named index and does not use the Username variable declared beforehand.
If you want to access an array variable with a dynamic name you can do it like this:
game.Players[Username]:BreakJoints()
additionally in roblox you could just use the following:
game.Players:GetPlayerByID(userId):BreakJoints()
Variables are very confusing in Lua sometimes.
For example, there are global and local variables.
Local variables are variables that can be forgotten/erased after the operation ends: local x = 2
Global variables are variables that stay within the game/application unforgotten, this is good with high scores and other neat things. x = 2 (Notice there isn't a "local" statement)

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