Lua Programming Help Thread

[seanpaul223]

Nice TurtlesPwn,
i've did it just like this:

--table for units
unit = {}
unit[1] = {x=10,y=10,health=100, exist = true}
unit[2] = {x=10,y=10,health=100, exist = true}
unit[3] = {x=10,y=10,health=100, exist = true}

--counter
c = 1


--main loop
while true do
---
for i=1,#unit do
----
if unit[i].health<=0 then unit[i].exist = false end --this makes the unit disappear from the screen when dead
end

--this cleans the sub-table containing the dead unit parameters.
while c<=#unit do
   if not unit[c].exist then table.remove(unit,c) end
       c=c+1	
end
if c>=#unit then c=1 end

I guess i did it according to what u said before.Anyway, this works fine.

[TurtlesPwn]

no, that's not what I said, thats one of the worse ways to do it.

replace

for i=1,#unit do
----
if unit[i].health<=0 then unit[i].exist = false end --this makes the unit disappear from the screen when dead
end

--this cleans the sub-table containing the dead unit parameters.
while c<=#unit do
   if not unit[c].exist then table.remove(unit,c) end
       c=c+1	
end
if c>=#unit then c=1 end

with

for i, thisunit in ipairs(unit) do
	if thisunit.health <= 0 then
		table.remove(unit,i)
	end
end

[slicer4ever]

tables in lua don't start at 0?

[TurtlesPwn]

no, they start at 1. they're weird....but to me starting at 1 is the more logical way to do it.

[_df_]

well tables dont naturally index at 0 but you can use 0 as a key foo[0] = "x" will work just fine, as long as you understand the difference between using a table like an array and using it like a dictionary.

[dan369]

So i need a bit of help with table.insert().
I have to variables, mapX, mapY. These are entered by the player. Then i need to insert the starting elements which are(will be) indexed to 0. So i was wondering about how i'd insert that info into a array. MapX is the length, MapY is the height of the array.

[TurtlesPwn]

table.insert(atable,athin gtoinsert,ifyouwantthepos itionatwhichtoinsertit)
atable[index] = athingtoinsert

[dan369]

I'm still stuck . So i have the table say called 'map'. Then i have this,

for i = 1, MapX do
     for j = 1, MapY do
          table.insert(map, 0);
               end
       end

Would that work? (btw thats off the top of my head)

[eldiablov]

Just test it ! You ask way too many questions. I worked out how to use table.insert within two minutes of testing and a bit of printing to the screen. Better yet, look at the DOCUMENTATION.

[dan369]

Just test it ! You ask way too many questions. I worked out how to use table.insert within two minutes of testing and a bit of printing to the screen. Better yet, look at the DOCUMENTATION.

Well i would if i was near a computer but i'm not you see. Otherwise i would. (i'm on my psp) . And i really haven't asked any coding question in a while.

[TurtlesPwn]

you need to better explain wth it is youre trying to do, because so far youve said ok i have mapx and mapy and you have to guess what exactly those are being used for and now help me with table.insert and also im using some for loops

[FaT3oYCG]

I'm still stuck . So i have the table say called 'map'. Then i have this,

for i = 1, MapX do
     for j = 1, MapY do
          table.insert(map, 0);
               end
       end

Would that work? (btw thats off the top of my head)

yes that would create a table full of 0's (not even multi dimensional) which doesnt seem so useful to me XD.

[dan369]

you need to better explain wth it is youre trying to do, because so far youve said ok i have mapx and mapy and you have to guess what exactly those are being used for and now help me with table.insert and also im using some for loops

I'm trying to make a initial blank canvas, the player will enter values (MapX, MapY). This would be the size of said canvas. Which should be an array like,
map = {
{0,0,0,0,}
}
Something like that.

[eldiablov]

And i really haven't asked any coding question in a while.

Your millions of threads on evilmana beg to differ.

[TurtlesPwn]

I'm trying to make a initial blank canvas, the player will enter values (MapX, MapY). This would be the size of said canvas. Which should be an array like,
map = {
{0,0,0,0,}
}
Something like that.

just make the tables manually dont bother with insert

for i = 1, mapY do
	map[i] = {}
	for j = 1, mapX do
		map[i][j] = 0
	end
end

[Nielkie]

map = {
{0,0,0,0,}
}
Something like that.

A two dimensional array? No.

Something like this:

map = {
	{0,0,0,0},
	{0,0,0,0},
	{0,0,0,0},
	{0,0,0,0}
}

[dan369]

just make the tables manually dont bother with insert

for i = 1, mapY do
	map[i] = {}
	for j = 1, mapX do
		map[i][j] = 0
	end
end

Would that make the two-dimensional array?

@Nielkie, yeah i kinda rushed my little example

My last question, how would i write that array to a file?

[Nielkie]

Umm...

for i = 1, mapY do
	for j = 1, mapX do
		file:write(map[i][j])
	end
end

[dan369]

Thanks nielkie
-=Double Post Merge =-

Your millions of threads on evilmana beg to differ.

Check the dates. I might have 'millions' of threads but it's not a crime to ask for a couple of questions/suggestions. You do know this is the Lua programming Help thread. You don't have to help anyone u know. Anyway i tried to test the output and the gd news is that it writes 0 to the .txt file. But it is no array there is no map = {
{0,0,0,0,0},
{0,0,0,0,0},
{0,0,0,0,0}
}
it is just a huge row of 0

[Nielkie]

Well obviously... you'll have to read the map back in...

for i = 1, mapY do
	for j = 1, mapX do
		map[i][j] = file:read(1)
	end
end

Though this is just a guide. You'll also have to store and read back the dimensions of the map. Of course, you'll have to create a more advanced way of storing each number, or what ever data type you choose to store in the array, so that each one is the same length in the file. I suggest 8-bit integers.

[dan369]

Could i just use this?

[FaT3oYCG]

i dont know can you use a function? you tell me!

[lukespalding]

i dont know can you use a function? you tell me!

ROFL

Dan, experiment dude find things out for yourself, then if your still stuck then ask questions but thats just my opinion.
Anyway to the point, a while ago i created a little Lua file from which you could create a table of values and save that said table to a .lua file and then you could load that table from that said file.
You'll get what i mean better when you actually see it, i'm not guaranteeing that is the most brilliant thing ever but it would help you get a leg up on what you are trying to do and hey every little helps.

http://www.megaupload.com/?d=2OQN2WD5

P.S i created this about 1 year ago . . . , Oh if you ever need a tile map i have one you could use, just give me a PM if you ever need it or help for that matter.

[dan369]

i dont know can you use a function? you tell me!

Ok, i should of been a bit more exact. I meant would it do what i want? Save a 2d array to a file, that's what i meant.

@Luke, i'd like to take a look at your example, but megaupload doesn't work for me . Though thanks, if say you could host on a site like sendspace, it would be grateful

Though lots of MapEditors have used that table.save() function, though i saw the output in a file and it wasn't the output i was hoping for, so that got my curious on the output hense why i asked the question,

[lukespalding]

Ok, i should of been a bit more exact. I meant would it do what i want? Save a 2d array to a file, that's what i meant.

@Luke, i'd like to take a look at your example, but megaupload doesn't work for me . Though thanks, if say you could host on a site like sendspace, it would be grateful

Though lots of Map Editors have used that table.save() function, though i saw the output in a file and it wasn't the output i was hoping for, so that got my curious on the output hense why i asked the question,

Of course i can Dan, here's the link . . .
http://www.sendspace.com/file/kh1bwr

hope this helps you with loading tables from a file.

[dan369]

Thanks Luke

[lukespalding]

Thanks Luke

Your Welcome!

[TurtlesPwn]

Would that make the two-dimensional array?

look at the code

make up a number for mapX and mapY, lets make each of them = 3

now run through the forloops in your head

and see what it makes

alternatively you could get something like TTLDE and test simple stuff on the psp on your own. or quit complaining that you're on your psp, because that really isn't any of our problems and if you can't test things out you shouldn't be asking for help.

[dan369]

I've done it now. At that moment in time, i was on my psp.

[TurtlesPwn]

I've done it now. At that moment in time, i was on my psp.

this is my point. dont keep asking questions that can be answered by testing simply because you arent able to test. wait until you can, try stuff out, and then if you still dont get it, ask.