Simple piece of code, supposed to work isn't working... I really can't understand this.
This is code:
local asd = 1
if not asd == nil then
print("works")
end
That's it, is not printing "works", ;-; sorry if I'm missing something.
Operator precedence fooled you:
if not asd == nil then
is equivalent to
if (not asd) == nil then
Try
if not (asd == nil) then
Sorry, answer was doing
local asd = 1
if asd ~= nil then
print("works")
end
I didn't even knew that ~= is a thing wow
Related
I am trying to write a string join function that will work with both tables and variable arguments as input. Here is what I have so far:
function join(separator, ...)
local result = ""
local vargs = {...}
local n = #vargs
for i = 1, n do
local varg = vargs[i]
if type(varg) == "table" then
result = join(separator, result, table.unpack(varg))
elseif varg ~= nil then
result = result..tostring(varg)
if i < n then
result = result..separator
end
end
end
return result
end
However, when I try to use it with the following input:
print(join(",", "1", "2", "3"))
print(join(",", {"a", "b", "c"}))
The output is this:
1,2,3
,a,b,c
I did not expect the , at the beginning of a,b,c.
From what I understand, it seems somehow the separator is getting added to the variable arguments when calling the function inside the function (recursiveness). But why is that? And how can I fix it? Thank you!
Try
...
if type(varg) == "table" then
varg = join(separator, table.unpack(varg))
end
if varg ~= nil then
...
Well uh sorry if it's not really useful but maybe it's because you put the: , into "" that it print the ,
I am having an error with one of my scripts in Roblox Studio. The line that shows that is a problem is Line 13. The script is for basically to weld when somebody sits on the seat, and to start up the TankGUI (Another script that is fine).
seat = script.Parent
function onChildAdded(part)
if (part.className == "Weld") then
while true do
local welde = seat:FindFirstChild("SeatWeld")
if (welde ~= nil) then
local sitted = welde.Part1.Parent
end
if (sitted.Name ~= script.Parent.Owner.Value) then
if (script.Parent.Owner.Value == "NoOne") then
script.Parent.Owner.Value = sitted.Name
print ("sitted steal")
else
print ("stolen!!")
local shipstealer = game.Workspace:FindFirstChild(sitted.Name)
if (shipstealer ~= nil) then
shipstealer.Humanoid.Jump=true
end
end
end
wait(0.2)
if (welde == nil) then
print("BreakLoop")
script.Parent.Owner.Value = "NoOne"
break end
end
end
end
--while true do
-- wait(0.5)
-- script.Parent.Parent.Name=script.Parent.Owner.Value .. "'s Ship"
--end
seat.ChildAdded:connect(onChildAdded)
Please excuse any poor co-operation or language barriers I'm having. I'm still a bit new here.
if (welde ~= nil) then
local sitted = welde.Part1.Parent
end
if (sitted.Name ~= script.Parent.Owner.Value) then
Since you're declaring sitted as local, it goes out of scope at end, so it's gone when you try to use it in that if, so you're actually using a nil global variable there. Do this instead:
local sitted
if (welde ~= nil) then
sitted = welde.Part1.Parent
end
if (sitted.Name ~= script.Parent.Owner.Value) then
That way it'll stay in scope until you're actually done with it.
I'm working on a project where I want to update the clock on screen say every 5 seconds unless the user inputs something. This is the code I have so far,
function thread1()
term.clear()
term.setCursorPos(1,1)
write (" SteveCell ")
local time = os.time()
local formatTime = textutils.formatTime(time, false)
write (formatTime)
print ("")
print ("")
for i=1,13 do
write ("-")
end
print("")
print ("1. Clock")
print ("2. Calender")
print ("3. Memo")
print ("4. Shutdown")
for i=1,13 do
write ("-")
end
print ("")
print ("")
write ("Choose an option: ")
local choice = io.read()
local choiceValid = false
if (choice == "1") then
-- do this
elseif (choice == "2") then
-- do that
elseif (choice == "3") then
-- do this
elseif (choice == "4") then
shell.run("shutdown")
else
print ("Choice Invalid")
os.sleep(2)
shell.run("mainMenu")
end
end
function thread2()
localmyTimer = os.startTimer(5)
while true do
local event,timerID = os.pullEvent("timer")
if timerID == myTimer then break end
end
return
end
parallel.waitForAny(thread1, thread2)
shell.run("mainMenu")
Unfortunately it's not working. If someone could help me with this, I would really appreciate it. Thanks :)
You want to do something like this (Im not doing the correct on screen drawing, only the time)
local function thread1_2()
-- both threads in one!
while true do
local ID_MAIN = os.startTimer(5)
local ID = os.startTimer(0.05)
local e = { os.pullEvent() }
if e[1] == "char" then
-- Check all the options with variable e[2] here
print( string.format( "Pressed %s", e[2] ) )
break -- Getting out of the 'thread'
elseif e[1] == "timer" and e[2] == ID then
ID = os.startTimer(0.05) -- shortest interval in cc
redrawTime() -- Redraw and update the time in this function!!!
elseif e[1] == "timer" and e[2] == MAIN_ID then
break
end
end
end
Also, ask this in the proper forum, you have more chance getting an answer there!
Another note, get more into event handling, it really helps.
FYI Lua doesn't have 'multi-threading' as in executing multiple routines simultaneously. What it does have is 'thread parking.' You can switch between routines (yielding) and switch back and it will resume where it left off, but only a single routine will be active at any given time.
This is my go-to Lua reference, which explains in detail:
http://lua-users.org/wiki/CoroutinesTutorial
local data={}
eventNewPlayer=function(n)
data[n]={tab="none"}
end
function eventChatCommand(n,c)
if c == "foo" then
data[n].tab = c
if data[n].tab == c then
ui.removeTextArea(90,n)
else
ui.addTextArea(90,"f"..string.rep("o",35),n,400,200,nil,nil)
end
end
end
table.foreach(tfm.get.room.playerList,eventNewPlayer)
It's a logical error the textarea does not appear whatsoever and I don't really see any error in the code mentioned above
When data[n].tab = c is executed, you are assigning the value of c to data[n].tab. This will happen every time that c == "foo".
Therefore, when you execute this:
if data[n].tab == c then
ui.removeTextArea(90,n)
else
ui.addTextArea(90,"f"..string.rep("o",35),n,400,200,nil,nil)
end
It will always execute the first part, and not the second part.
It is my first lua project and i have a trouble with skipping part of my code. I want the code to stop after part "Cool". So if i write good and it answers cool i want the rest of the code to stop since after that the next question is not relative anymore.
How it works:
Code says: Hello
You say: anything
Code says: How are you?
You say: good
after you say good it will say cool.
If you say anything other than good it will ask "Why?"
e.g. you say: bad
Code says: It will be alright
I want it to stop after "cool" and skip out the further part of the code.
os.execute(" cls ")
print("Hello")
odp = io.read()
if odp == string then
end
tof = true or false
print("How are you?")
odp2 = io.read()
if odp2 == "good" then print("Cool") tof = true
else print("Why?") tof = false
if tof == true then os.execute(" pause ")
end
end
odp3 = io.read()
if odp3 ~= math then print("It will be alright")
print("Okay, I have to go see you.")
end
os.execute(" pause ")
When you compile code, it becomes the body of a function. The prototypical way of exiting a function is with a return statement. A function can have zero or more return statements.
But, since you want to exit the program, you can instead call os.exit().
You've just got to nest your "if" statements differently. All you need to do is put the rest of the code into the "else" part of your "if" statement, like this:
os.execute(" cls ")
print("Hello")
odp = io.read()
if odp == string then
end
tof = true or false
print("How are you?")
odp2 = io.read()
if odp2 == "good" then
print("Cool")
tof = true
else
print("Why?")
tof = false
if tof == true then
os.execute(" pause ")
end
-- You had an "end" here.
odp3 = io.read()
if odp3 ~= math then
print("It will be alright")
print("Okay, I have to go see you.")
end
os.execute(" pause ")
end -- You literally just need to move it here.
That way, it only gets input from the user after it asks for it, and only if the user doesn't answer, "good" to the "How are you?" question.
Note that I re-indented the code, but it's still the same code in the same order. I just made it more standard-looking and easier to visually see the structure of the program.