Setting a variable in a for loop (with temporary variable) Lua

Question

I have a for loop in lua, and I'm trying to set variables inside that for loop using the iterator variable. I need it to set these variables:

damage1
damage2
damage3
damage4
damage5
damage6
damage7
damage8
damage9
damage10
damage11

Of course I'm not going to assign them all, as that would be breaking the rules of D.R.Y. (Don't Repeat Yourself). This is what I figured would work:

for i = 0, 11 do
    damage..i = love.graphics.newImage('/sprites/damage/damage'..i..'.png')
end

Don't mind the love.graphics.newImage(), that's just a function in the framework I'm using. Anyways, can someone help?

Thanks in advance.

possible duplicate of How do I make a dynamic variable name in Lua? — finnw
– finnw, Commented Jun 23, 2013 at 20:51

lhf · Accepted Answer · 2013-06-23 20:34:09Z

3

If you want to set global variables, set _G["damage"..i].

If you want to set local variables, you're out of luck.

Consider setting damage[i] instead.

edited Jun 23, 2013 at 20:34

answered Jun 23, 2013 at 20:13

lhf

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1 Comment

hexagonest Over a year ago

Thanks for the fast answer! I will be able to access this variable as if it was a normal variable, yes?

hugomg · Accepted Answer · 2013-06-23 20:28:11Z

2

If your variables are local variables, its impossible to do what you want since Lua erases the names during compilation. If your variables are properties of a table (like global variables are) then you can use the fact that table access is syntax sugar for accessing a string property in a table:

--using a global variable
damage1 = 17

--is syntax sugar for acessing the global table
_G.damage1 = 17

--and this is syntax sugar for acessing the "variable1" string property
--of the global table
_G["damage1"] = 17

--and you can build this string dynamically if you want:
_G["damage"..1] = 17

However, as lhf said, it would probably be much more simpler if you stored the variables in an array instead of as separate variables:

damages = {10, 20, 30, 40}

for i=1,4 do
    damages[i] = damages[i] + 1
end

answered Jun 23, 2013 at 20:28

hugomg

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1 Comment

hexagonest Over a year ago

I made a local table, instead of making a local variable.

Blab · Accepted Answer · 2013-06-24 19:16:06Z

0

Wouldn't this be the best thing to do?

damages = {}

for i = 0,11 do
    table.insert(damages, love.graphics.newImage("/sprites/damage/damage"..i..".png"));
end

And then call by damages[0], damages[1]. etc.

answered Jun 24, 2013 at 19:16

Blab

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