How to loop this table

[Hero192]

Hey, I don't know how to loop this kind of tables

for example:

local ranks = { 
["Fireman"] = { 
    {"level1", 1}, 
    {"Level2", 2}, 
    {"Level3", 3}, 
    {"Level4", 4}, 
    } 
} 

[Dimos7]

Example

local ranks = { 
  ["Fireman"] = { 
  {"Level1", 1}, 
  {"Level2", 2}, 
  {"Level3", 3}, 
  {"Level4", 4} 
  } 
} 
  
function rankSet() 
     for _, v in ipairs (ranks) do 
         --code what you want 
     end 
end 

Edited February 17, 2016 by Guest

[-Doc-]

It's ipairs

local ranks = { 
  ["Fireman"] = { 
  {"Level1", 1}, 
  {"Level2", 2}, 
  {"Level3", 3}, 
  {"Level4", 4} 
  } 
} 
  
function rankSet() 
     for _, v in ipairs (ranks) do 
         --code what you want 
     end 
end 

[Bonus]

@-Doc- Absolutely wrong.

The index is a string, not integer, ipairs won't work.

The best way to handle this is:

local ranks = { 
  ["Fireman"] = { 
  {"Level1", 1}, 
  {"Level2", 2}, 
  {"Level3", 3}, 
  {"Level4", 4} 
  } 
} 
  
function rankSet() 
     for faction, array in pairs ( ranks ) do      -- index is string, so for i=1, #ranks or ipairs won't work here 
          -- faction is "Fireman" here --- 
          for i=1, #array do        -- that's way faster than ipairs 
               -- array[i][1] is "Level1", array[i][2] is 1 in the first loop -- 
          end 
     end 
end 

The difference between ipairs and for i=1, #array are:

ipairs is slow and stops when the index isnt going from i=1 to n without space like:

"1, 2, 3, 5, 6, 7, 8"

ipairs will stop at 3.

for i=1, #array is faster, but doesnt stop.

"1, 2, 3, 5, 6, 7, 8"

It will give out an error because there is no array[4].

But you can handle it by asking:

if array[i] then 

and it's still faster than ipairs.

Some guys use ipairs with getElementsByType:

DON'T DO THAT

Thats stupid, it's slow and useless.

Use that:

local players = getElementsByType ( "player" ) 
for i=1, #players do 
     -- players[i] is the player 
end 

That's faster

[Hero192]

Tnx alot, but who told you it's faster than pairs & ipairs?

[Bonus]

Jusonex, some LUA-Tutorial-Websites and I tested it myself.

This website is pretty good:

https://springrts.com/wiki/Lua_Performa ... _for-loops

[Yazir]

Code will run slower and harder if loops will be longer?