Sorting a table in lua

[McGuffin]

Hi, i am trying to figure how to sort a table with multiple entries

Here is my problem.
I have something like that

tArray["name1"] = { param1 = 10, params2 = 20, param3 = 50}
tArray["name2"] = { param1 = 5, params2 = 45, param3 = 132}
tArray["name3"] = { param1 = 8, params2 = 55, param3 = 10}

now i want to sort tArray, by using the param1 order.
so i tried somthing like that

function sortParam1(a,b)
   return a[1]<b[1]
end

table.sort(tarray, sortParam1)

but that doesnt work...
is everyone know a way to do this?

[stjobe]

lua.org has something to say on the issue.
As has the lua-users.org wiki.
And even Stack Overflow.

[lyravega]

Uhm, I don't know if table.sort works for tables; I think it only works for arrays (tables with numeric keys in order, 1...n). Don't take my word on it though.

The other thing is, in your function, it says "a[1]<b[1]", but what is a[1]? Shouldn't it be a.param1?

[McGuffin]

Originally Posted by stjobe lua.org has something to say on the issue. As has the lua-users.org wiki. And even Stack Overflow.

well, i ve already found every links you provide (and even more).
but none of them is an answer to my question (they are all related to array with a single params), and this is why I am asking here.

Originally Posted by lyravega Shouldn't it be a.param1?

That was my first thought , and that doesnt work either, this is why I tried a more direct way with the index ...
this is tricking me i know how to do that in delphi or c++ but not in lua...

[SinusPi]

There's no way to do that, simply. Your table isn't even sorted by the keys, not to mention the value of the param1 attribute.

But, you can do something else.

tArray={}
tArray["name1"] = { param1 = 10, params2 = 20, param3 = 50}
tArray["name2"] = { param1 = 5, params2 = 45, param3 = 132}
tArray["name3"] = { param1 = 8, params2 = 55, param3 = 10}

bag = {}
for k,v in pairs(tArray) do
  table.insert(bag,{key=k,data=v})
end

table.sort(bag,function(a,b) return a.data.param1<b.data.param1 end)

for i,t in ipairs(bag) do
  print(t.key)
end

[McGuffin]

thank you SinusPi, it works like a charm ^^

[stjobe]

Originally Posted by McGuffin well, i ve already found every links you provide (and even more). but none of them is an answer to my question (they are all related to array with a single params), and this is why I am asking here.

I'm happy you got your answer, and I'm sorry I came off as a bit ... "RTFM, dude". Not my intention