[Function] Array random sort

[Mock]

Some times you got an array like this:

arr = {
   {'bla',3,7},
   {'ble',{4,5},5},
   {'omg',0,2},
   {whatever},
    ... 
   {n}, 
}

and you HAVE to sort this randomly, you cant just call arr[math.random(1,#arr)], sou what you do?
You can declare like 10 of this same array and call one random of these or sort all them easly.

function randomSort(arr)
	local sorted = {}
	local rand2
	local rand
	local mem
	for i=1,#arr do
		sorted[i] = arr[i]
	end
	if (#arr <= 1) then
		return sorted;
	end
	for i=1,(#arr)^2 do	    
		repeat
			rand = math.random(1,#sorted)
			rand2 = math.random(1,#sorted)
		until rand ~= rand2
		mem = sorted[rand]
		sorted[rand] = pgtss[rand2]
		sorted[rand2] = mem
	end
	return sorted
end

This code basicaly copy the content of arr to another array. I cant just use sorted = arr because in some metatables form lua if you do this you going to use sorted as a pointer to content of arr. If you dont know what i am sayig, trust me, in some cases without what i did it is going to be wrong.
so then it run a for size^2 to arr, then a random runs taking 2 possible positions. So the code change the content of this positions. if selected 5 an 7 position and inside is "hai" and "bye", so the in 5 will contain "bye" in 7 "hai"

As it run #arr^2 times the arr will be random sorted

 

[Synthetic_]

this is really useful, thanks