shuffling a table

Games
#1

Hello 

I am messing around with a game Match3Gems to help learn the fundamental of lua and corona.  The screenshot will show this.

I am trying to to shuffle the table when the player presses the button, but I am having sum trouble doing this.

The code that fills the table is 
[lua]

local gemsTable = {}

for i = 1, 8, 1 do 

gemsTable[i] = {}

for j = 1, 8, 1 do 
gemsTable[i][j] = newGem(i,j) 

end 
end 
[/lua]

I came across this code online but cant get it working

[lua]

function table.shuffle(t) 
math.randomseed(os.time()) 
assert(t, “table.shuffle() expected a table, got nil”) 
local iterations = #t 
local j 
for i = iterations, 2, -1 do  
j = math.random(i) 
t[i], t[j] = t[j], t[i] 
end 
end 

function shuffleGameButton(event) 
for i = 1, 8, 1 do  
gemsTable[i] = i 
for j = 1, 8, 1 do  
gemsTable[j] =j 
end 
end 
[/lua]

Does anyone know what the best way to get this done

Thanking You

Alan Fletcher

#2

That shuffle code is unreadable the way it is pasted.  Here is what I use:

local function shuffleTable(tablename) local t = tablename function table.shuffle(t) math.randomseed(os.time()) assert(t, "table.shuffle() expected a table, got nil") local iterations = #t local j for i = iterations, 2, -1 do j = math.random(i) t[i], t[j] = t[j], t[i] end end return table.shuffle(t) end
#3

Thanks for the help, this does rearange the table but the display doesnt update, thanks for the help

#4

Correct, this function takes a table, shuffles it, then returns the table with shuffled elements.  It’s up to you to update the UI.

#5

any idea what the best way to do that is

#6

How are you creating the display objects now?  I would create a function that first removes the current display objects (if they exist), then shuffles the table, then creates the new display objects.  Then in your “Shuffle” button code call this function.

#7

[lua]newGem = display.newCircle(-100, i*70-20, 35)[/lua]

and entering into the table via

[lua]

for i = 1, 8, 1 do

        gemsTable[i] = {}

        for j = 1, 8, 1 do

            --gemsTable[i][j]:setReferencePoint(display.CenterReferencePoint)

            gemsTable[i][j] = newGem(i,j)

    

         end

     end

[/lua]

#8

That shuffle code is unreadable the way it is pasted.  Here is what I use:

local function shuffleTable(tablename) local t = tablename function table.shuffle(t) math.randomseed(os.time()) assert(t, "table.shuffle() expected a table, got nil") local iterations = #t local j for i = iterations, 2, -1 do j = math.random(i) t[i], t[j] = t[j], t[i] end end return table.shuffle(t) end
#9

Thanks for the help, this does rearange the table but the display doesnt update, thanks for the help

#10

Correct, this function takes a table, shuffles it, then returns the table with shuffled elements.  It’s up to you to update the UI.

#11

any idea what the best way to do that is

#12

How are you creating the display objects now?  I would create a function that first removes the current display objects (if they exist), then shuffles the table, then creates the new display objects.  Then in your “Shuffle” button code call this function.

#13

[lua]newGem = display.newCircle(-100, i*70-20, 35)[/lua]

and entering into the table via

[lua]

for i = 1, 8, 1 do

        gemsTable[i] = {}

        for j = 1, 8, 1 do

            --gemsTable[i][j]:setReferencePoint(display.CenterReferencePoint)

            gemsTable[i][j] = newGem(i,j)

    

         end

     end

[/lua]