Specific Table Location

local user = "user1"

local uTable = {
[1] = "user1",
[2] = "user2",
}

for k, v in pairs(uTable) do
  if user == uTable[v] then
	print(k)
	break
  end
end

for k,v in pairs(uTable) do
  if user == uTable[k] then
	print(k)
	break
  end
end

for k,v in pairs(uTable) do
  if user == v then
	print(k)
	break
  end
end

local userIdx
for k,v in pairs(uTable) do
  if user == v then
    userIdx = k
    break
  end
end

--# you now know out here which index they were from the userIdx variable

local uTable = {
  ["user1"] = "user password",
  ["user2"] = "qwerty",
  ["user3"] = "S3cure Pa55w0rD
}

local user = "user1"
local pass = uTable[user]

theoriginalbit, on 04 October 2013 - 11:07 AM said:

You were close with your loop that you provided, what you've done wrong is that v is actually the value in the table, k is the key, therefore you want to do the following

 for k,v in pairs(uTable) do if user == uTable[k] then print(k) break end end 

However, what's the point of looking up the value again, when we already have it, so instead we can compare against v.

 for k,v in pairs(uTable) do if user == v then print(k) break end end 

Also you would want to actually store the index for later, something like so

 local userIdx for k,v in pairs(uTable) do if user == v then userIdx = k break end end --# you now know out here which index they were from the userIdx variable 

Lastly I have a feeling this is going to be used as some kind of login system, and that you're using the position the user is in the table to retrieve their password from another table? Yes? If so then I suggest doing the following change to your table layout/structure, its much simpler and requires no loops meaning that it is far more efficient.

 local uTable = { ["user1"] = "user password", ["user2"] = "qwerty", ["user3"] = "S3cure Pa55w0rD } 

The reason that the above table structure is so much better is that we can quickly and easily perform lookups on the table, like so

 local user = "user1" local pass = uTable[user] 

In the above code the pass variable will either contain the user's password, or if that user didn't exist it will be nil. Expending upon the above method can make for some very powerful, extensible, and efficient login systems (all be it not very secure having hardcoded usernames/passwords in the table, but that's a different topic).

 local uTable = { ["user1"] = "user password", ["user2"] = "qwerty", ["user3"] = "S3cure Pa55w0rD } 

smurfofiel, on 04 October 2013 - 04:51 PM said:

but if i want to do it your way like:

 local uTable = { ["user1"] = "user password", ["user2"] = "qwerty", ["user3"] = "S3cure Pa55w0rD } 

how can i check if a certain passwords matches a certain player name. for example i get a user name from a read event, and the username is "mike" and i have a table like: ["mike"] = "1234", how can i check that 1234 belongs to "mike"?

local uTable = {
  ["mike"] = "1234",
}

local user = read()
local pass = read()

if uTable[user] == pass then
  print("The password was correct")
else
  print("The username or password is incorrect")
end