[Lua][Error]attempt to index(a nil value)

error on line 21

local pie = ""
local x = ""
local y = ""
local t = {}
rednet.open("top")
function getDest()
  g = fs.open("dest","r")
  print(g.readAll())  
  g.close()
end
function setDest(x,y)
  t[x] = {}
  t[x][1] = y
end

function send()
  print("destonation")
  c = read()
  if c == hi[c] then
	sleep(1)
	rednet.send(tonumber(t[c]["comp"]),"open")
	sleep(1)
  end
end
function rec(o)
  if o == "open" then
	redstone.setOutput("left",true)
	sleep(2)
	redstone.setOutput("left",false)
  end
end	
getDest()
setDest(x,y)
hi[x] = {}
hi[x][1] = y
sleep(1)
while true do
  shell.run("clear")
  a,b,c,d,e = os.pullEvent()
  if a == "modem_message" then
	rec(e)
	elseif a == "key" then
	send()
  end  
end

It expects that x is a variable. Put it into quotations and then it would be fine:
t['x'] = {}

Engineer, on 21 April 2013 - 09:59 PM said:

It expects that x is a variable. Put it into quotations and then it would be fine:
t['x'] = {}

I think x is a variable, since its in the function… bad indentation… OP please use [code][/code] tags and re-indent the code so it is more readable

theoriginalbit, on 21 April 2013 - 10:00 PM said:

Engineer, on 21 April 2013 - 09:59 PM said:

It expects that x is a variable. Put it into quotations and then it would be fine:
t['x'] = {}

I think x is a variable, since its in the function… bad indentation… OP please use [code][/code] tags and re-indent the code so it is more readable

It was Indented when i made it and copied the editor on here doesnt like tabs

@BIT:
Lol, didnt even saw it.. I should have looked better though…

@OP
Are you sure you are using the parameters?

jamzam90, on 21 April 2013 - 10:02 PM said:

It was Indented when i made it and copied the editor on here doesnt like tabs

Unless it is in code tags….

now your line

setDest(x,y)

where are x and y meant to be coming from? because at the moment they are nil and that is causing your problems

Engineer, on 21 April 2013 - 10:03 PM said:

@BIT:
Lol, didnt even saw it.. I should have looked better though…

@OP
Are you sure you are using the parameters?

As far as i can tell I am.

theoriginalbit, on 21 April 2013 - 10:05 PM said:

jamzam90, on 21 April 2013 - 10:02 PM said:

It was Indented when i made it and copied the editor on here doesnt like tabs

Unless it is in code tags….

now your line

setDest(x,y)

where are x and y meant to be coming from? because at the moment they are nil and that is causing your problems

the x and y are coming from the getDest() function

- derping here


Well.. X abd y are never defined as variable.. Thats your problem

Changed the Main post

does the file 'dest' exist on the computer?

I suggest this code

function getDest()
  local g = fs.open('dest', 'r')
  if g then
    print(g.readAll())
    g.close()
  else
    -- the file doesn't exist, create it here and set all your values to defaults
  end
end

the file dest does exist

then what line is the new error happening on?

its happening on line 21

@jamzam90:
You have to post your whole code or this is a guessing game and we can't help you properly.
You don't go to your doctor with only the foot that is hurting. You always take your whole body, don't you? ;)/>

@jamzam90:
You have to post your whole code or this is a guessing game and we can't help you properly.
You don't go to your doctor with only the foot that is hurting. You always take your whole body, don't you? ;)/>

I hadnt noticed some of it was missing

Do what Engineer said, i.e. replace all t[x] with t["x"].
Ort as an alternative which works the same: replace it with t.x
Do this with all the tables (hi[x] -> h["x"] or h.x)

Edit - to explain a little as to why:
fruits[abc] will access the table fruits with the key in abc.
abc is a variable here, so whatever is in abc will be the key, not "abc".
If abc == "yummy", then fruits[abc] is the same as fruits["yummy"].

Also, to make it easier to access named keys, Lua allows to replace fruits["yummy"] with fruits.yummy