7 replies to this topic

[exploder]

Hello.

My lights system is failing to launch properly.I am getting error every time I try to launch it and I can't seem to find the problem, but I guess it got to do something with functions.

Any help would be appreciated.

Here's to code:

on = "1"
off = "2"
menu()
function menu()
term.clear()
term.setCursorPos(1,1)
print("	  +--------------+")
print("	  :Lights Control:")
print("	  +--------------+")
print("	  :1.To turn ON. :")
print("	  :2.To turn OFF.:")
print("	  +--------------+")
write("Your Choice:")
input = read()
if input == on then on() end
elseif input == off then off()
else menu()
end

function on()
term.clearLine()
print("Lights are turning on")
rs.setOutput("left",true)
sleep(1)
menu()
end
function off()
term.clearLine()
print("Lights are turning on")
rs.setOutput("left",false)
sleep(1)
menu()
end

And here is the picture of the error:

Spoiler

I couldn't add png extension to this forum, so you'll have to open this link.
http://imageshack.us...1020015613.png/

Thank you.

[Espen]

Remove the 'end' of the following line (to make the 'elseif' of the line after that part of it again):

if input == on then on() end

It's always If ... elseif ... end and not If ... end ... elseif ... end.
Or in other words: An If only ends once, and any elseif's are between the If and the end.

[PixelToast]

also on sould be "on" when comparing it to input

[exploder]

Espen, on 19 October 2012 - 11:17 PM, said:

Remove the 'end' of the following line (to make the 'elseif' of the line after that part of it again):

if input == on then on() end

It's always If ... elseif ... end and not If ... end ... elseif ... end.
Or in other words: An If only ends once, and any elseif's are between the If and the end.

PixelToast, on 19 October 2012 - 11:40 PM, said:

also on sould be "on" when comparing it to input

Thank you for helping, but now when I fixed that misplaced end I get an error: startup:3: attempt to call nil.
I tried to edit the code, but with no luck so far.So where is the problem now?
Thank you.

[ChunLing]

You didn't have an extra end, you had an end in the wrong place. By removing the end, instead of moving it where it belonged, you made it so that the function definition of menu() doesn't close and is thus undefined.

Of course I'm just guessing, because you didn't post the modified code.

[Espen]

exploder, on 20 October 2012 - 07:11 AM, said:

[...]
Thank you for helping, but now when I fixed that misplaced end I get an error: startup:3: attempt to call nil.
I tried to edit the code, but with no luck so far.So where is the problem now?
Thank you.

It tells you that on line 3 it attempted to call nil.
"Attempt to call nil" is an indicator for trying to call a function that doesn't exist.
In your case on line 3 there is "menu()".
But you haven't written the function up to that point. Only after your call to menu() did you write the actual method.
The problem is that in Lua you have to define a function before you call it.

So in this case, just move the call to menu() below the actual implementation of the function.
Then that error shouldn't appear anymore.

Cheers />

[exploder]

Espen, on 20 October 2012 - 11:04 AM, said:

exploder, on 20 October 2012 - 07:11 AM, said:

[...]
Thank you for helping, but now when I fixed that misplaced end I get an error: startup:3: attempt to call nil.
I tried to edit the code, but with no luck so far.So where is the problem now?
Thank you.

It tells you that on line 3 it attempted to call nil.
"Attempt to call nil" is an indicator for trying to call a function that doesn't exist.
In your case on line 3 there is "menu()".
But you haven't written the function up to that point. Only after your call to menu() did you write the actual method.
The problem is that in Lua you have to define a function before you call it.

So in this case, just move the call to menu() below the actual implementation of the function.
Then that error shouldn't appear anymore.

Cheers />

Thank you, this worked.

[Orwell]

PixelToast, on 19 October 2012 - 11:40 PM, said:

also on sould be "on" when comparing it to input

No it shouldn't, on is a variable defined as the string "1". And that's what he's polling for. (So you did that right exploder /> )