Question

I’ve just started learning corona and lua, my 1st project is to make a little dice game and Ive just started it! heres the dice object…

    --declare table + metatable

    local dice = {}

    local dice_mt = {__index = dice}


    --CONSTRUCTOR 

    function dice.new(ypos, xpos) 

    local newdice = {xpos = xpos, ypos = ypos,dicetext = display.newText("X", 50*xpos , 50*ypos , nil, 50)} 

    --dicetext = display.newText(facevalue, 50*xpos , 50*ypos , nil, 50)

    return setmetatable(newdice, dice_mt) 
    end

    --rolldice function

    function dice:rolldice()

    self.dicetext.text = math.random(0,6) 

    end

    return dice

the game is to have a grid of 25 dice which can be rolled (with rolldice function above)
Heres my main.lua

    display.setStatusBar(display.HiddenStatusBar)

    local diceclass = require ("dice")

    for i = 1, 5, 1 do

    local die = diceclass.new(i,i)

    i = i+1

    end

    die:rolldice()

I’m trying to generate the grid of dice programatically (atm I am just generating 5 dice(just text) in a diagonal line. Thats fine so far but my problem is running the rolldice function. It works when there is only 1 dice but not when there is more.
I’m guessing the problem is that I have all these instances of the class with the same name.. Is there a way to give them different names programmatically as I create them in my for loop? Or is there some better way of doing this? Thanks!

Answer 1

local variables are so named because they are local to the scope in which they are defined. die is defined within the for loop. Therefore, it stops existing once you leave the for loop.

If you want to create an array of die objects, you need to create an array which is accessible outside of the loop, then add the die objects to this array.

Also, i = i+1 is counter-productive, since Lua knows how to increment loops itself. Also, it may lead to undefined behavior.