table.remove

[IIYAMA]

I have a problem with removing data from a table.

When I use table.remove the table will automatic change.

Sample:

local A = createObject(...,...,...,..)

local B = createObject(...,...,...,..)

local myTable = {A,2,8,B}

for i, v in ipairs (myTable) do

if not isElement( vehicle ) then

table.remove(myTable,i)

end

end

When I do this:

-- {A,2,8,B} --

First loop A won't be removed because it is an element.

Next 2 is a number so will be removed. (i=2)*

8 will be at location [2] because of table.remove(myTable,i=2)*.

But 8 since is there.... he won't remove

Index during table.remove

What is the best way to solve this?

[csiguusz]

for i, v in ipairs ( myTable ) do 
    while not isElement( myTable[ i ] ) do 
        table.remove( myTable, i ) 
    end 
end 

[IIYAMA]

But it will still skip some data?

[csiguusz]

No, I don't think it will skip any.

[IIYAMA]

airplanes_weapon\server.lua:58 Aborting; infinite running script in airplanes_weapons

but it will go on for ever.

[csiguusz]

Hm, I made a few tests with it and worked perfectly. So lets find out an another method..

[IIYAMA]

Well I think I let the inpairs loop twice,

[csiguusz]

That's an exciting problem, but I think I solved it now.

I know what was wrong in the first one. But now I had an another idea:

    local temp = {} 
    for i, v in ipairs (myTable) do 
        if not isElement( myTable[i]) then 
            table.insert( temp, i ) 
        end 
    end 
    for i, v in ipairs(temp) do 
        table.remove( myTable, v-(i-1)) 
    end 
    temp = {} 

Won't run for ever, and will remove every value from the table, wich fits the condition.

Maybe there is some easier solution, I'll be thinking about it.

[Anderl]

for i, v in ipairs ( myTable ) do 
    while not isElement( myTable[ i ] ) do 
        table.remove( myTable, i ) 
    end 
end 

In his example, indexes are numbers, so this will remove everything from the array. Also, "myTable[ i ]" is not needed inside an iteration statement.

[csiguusz]

Indexes are always number, aren't they? And it wont remove everything, just in some cases it doesn't stop.

But I fixed it:

    for i, v in ipairs ( myTable ) do 
        while myTable[ i ] and not isElement( t[ myTable ] ) do 
            table.remove( myTable, i ) 
        end 
    end 

Edit: I know an index can be anything (e.g. table["something"] = 1 ). But in this case i would not call it index. Or do you still call it so?

[IIYAMA]

Indexes are always number, aren't they? And it wont remove everything, just in some cases it doesn't stop.

But I fixed it:

    for i, v in ipairs ( myTable ) do 
        while myTable[ i ] and not isElement( t[ myTable ] ) do 
            table.remove( myTable, i ) 
        end 
    end 

  
  
for i, v in ipairs ( myTable ) do 
        while myTable[ i ] and not isElement( v[i ] ) do 
            table.remove( myTable, i ) 
        end 
    end 

btw my element I need to check is here: v[1]

v[2] = weapon1

v[3] = weapon2

element, weapon1, weapon2 = unpack(v)

like this?

Note: while is dangerous stuff, even my intel boxed can crash of it....

Edited February 21, 2013 by Guest

[csiguusz]

Ahh, i messed up a bit the variables sorry, will fix it.

edit:

for i, v in ipairs ( myTable ) do 
    while myTable[ i ] and not tonumber( myTable[ i ] ) do 
        table.remove( myTable, i ) 
    end 
end 
  

Edited February 21, 2013 by Guest

[Anderl]

Indexes aren't always numbers, they can be anything else (but by default, unless you add them by yourself, it will be numbers). And yes, in your example it will remove everything since no index is an element.

On your last code, I didn't get some things:

while myTable[ i ] 

I already said you don't need that in iteration statements.

not isElement( t[ myTable ] ) do 

Okay.. What is that?

@IIYAMA, it's still not right. 'v' is the value, not an array. You can't do "v", it doesn't even make sense.

[IIYAMA]

I forgot this:

my element I need to check is here: v[1]

v[2] = weapon1

v[3] = weapon2

element, weapon1, weapon2 = unpack(v)

is this possible?

(myTable[ i ])[1]

[csiguusz]

not isElement( t[ myTable ] ) do 

This really doesn't makes sense, just forget to change every variable cause i tested it with something else, it's fixed now .

while myTable[ i ] 

Just try it with v instead of myTable[ i ] . After it removed one value, v won't be equal to myTable[ i ].

[IIYAMA]

aha got it, thank you

server

    for i,vehicle in ipairs (weaponObjectsVeh) do 
        while weaponObjectsVeh[ i ] and not isElement(weaponObjectsVeh[ i ]) do 
            table.remove(weaponObjectsVeh,i) 
        end 
    end 

client

        for i, v in ipairs (weaponObjectsVeh) do  
            --if not isElement(v[1]) then 
            while weaponObjectsVeh[ i ] and not isElement( (weaponObjectsVeh[i])[1] ) do 
                local vehicle2,weapon1,weapon2 = unpack(weaponObjectsVeh[i]) 
                destroyElement (weapon1) 
                if isElement(weapon2) then 
                    destroyElement (weapon2) 
                end 
                table.remove(weaponObjectsVeh,i) 
            end 
        end 

can it be smaller? because I call this index like 4x.

[csiguusz]

What's this? (weaponObjectsVeh)[1] ? Is it working so? The [1] isn't needed.

And what do you mean by smaller? I don't have a better idea, sorry

[IIYAMA]

(weaponObjectsVeh)[1]

= weaponObjectsVeh

theVehicle = v[1]

attached to the vehicle.

weapon1=v[2]

weapon2=v[3]

I can't check a "table" if it is an element.

When the vehicle get removed(gone) this filter will remove the weapons from the vehicles. The server table and the client together are working with the same data. Why I work with tables instead of element data is that I can decide when I send data to those players. If a player is in the spawn menu, he should start downloading new data at moments he really joins other players.

Also when they are doing a minigame, it isn't necessary to download those data.

Thank you again.

[csiguusz]

So v is an another table, i got it, and of course: you are welcome.

[Anderl]

Third time I repeat this: You do not need to call the index from the array (I mean this: myTable, it SHOULD be simply i)!

[csiguusz]

Could you please explain why not? myTable != i

[Anderl]

Because i is already the value, there is no need to get it again ( I also did some tests on the LUA interpreter and the condition "table == i" was false.

[csiguusz]

I is not the value, it is the index. " myTable == v". And its needed to get it again after we removed one value from the table because so every item in the table after the removed one "went back" one step, and so it can check that the new value that is now on the place of the removed one should be also removed or not ( in this case go to the next value).

[Anderl]

I was not talking about array values. I was saying 'i' was already the value from the array.

[csiguusz]

Sorry I still don't understand. '"i' was already the value from the array?" Hm... In my for loop 'i' was the index and 'v' was the value of the table (array?).