Is there any easy method to randomise an array

[songdg]

I want to made that Array := [Item1, Item2, ..., ItemN] randomised.

[Chunjee]

.shuffle doesn't get much easier. https://biga-ahk.github.io/biga.ahk/#/?id=shuffle

Code: Select all

A.shuffle([1, 2, 3, 4])
; => [4, 1, 3, 2]

A.shuffle(["barney", "fred", "pebbles"])
; => ["pebbles", "barney", "fred"]

[boiler]

Using native AHK (use v1.1.29 or later):

Code: Select all

Arr := RandomizeArray(["Howard", "Robin", "Fred", "Gary", "Ronnie"])

; display contents of Arr:
for i, v in Arr
	out .= v . A_Space
MsgBox, % out
return

RandomizeArray(arr) {
	newArr := []
	loop {
		Random, rand, 1, arr.Count()
		newArr.Push(arr.RemoveAt(rand))
	} until !arr.Count()
	return newArr
}

Caveat: This works if the items to be shuffled are strings or numbers, but not with an array of objects. To make it work with objects as well would be significantly slower, so there's a trade-off.

[A_AhkUser]

Inspired by JEE_StrRept by jeeswg:

Code: Select all

array := RandomizeArray(["Howard", "Robin", "Fred", "Gary", "Ronnie"])

for i, v in array, out := ""
	out .= v . A_Space
MsgBox, % RTrim(out)
return

RandomizeArray(arr) {
	loop % count:=arr.Count(ranStr:="") {
		Random, rand, 1, % count
		ranStr .= "{" . rand . "}" . A_Space
	}
	return StrSplit(Format(RTrim(ranStr), arr*), A_Space)
}

cheers

A_AhkUser

[teadrinker]

Code: Select all

Arr := RandomizeArray(["Howard", "Robin", "Fred", "Gary", "Ronnie"])
for k, v in Arr
   str .= v . " "
MsgBox, % str

RandomizeArray(Arr) {
   static d := Chr(1)
   for k, v in Arr
      str .= (str = "" ? "" : d) . v
   Sort, str, D%d% Random
   Return StrSplit(str, d)
}

[Helgef]

Hello, very nice to see you back again @A_AhkUser .

Code: Select all

loop % count:=arr.Count(ranStr:="") {

This is unacceptable though . (count accepts exactly zero parameters)

Cheers.

[A_AhkUser]

@teadrinker
Your answer is, as always, great and - unlike mine - as closely as possible to the question :"Is there any easy method to randomise an array?": your function is maybe one of the most transparent way to achieve this. Nevertheless, I think it is preferable in this case to handle a list by its indexes rather than its values - on which you have a priori no control whatsoever - or, at least, less control (e.g. values can be huge strings).

@Helgef

(..) back again (...)

Yes back again, me and my deplorable coding way to write... I proceeded from the assumption - more than questionable, actually - that if the script doesn't throw an exception and gives the expected output, it is "acceptable"... Besides, it seems I'm here once again guilty of an excess of enthusiasm (that perhaps one will excuse me as one of its motive is here a symbolic debt): actually, my function does randomize but allows duplicates.

@Boiler Your function is fine but I would like to underline one point: unlike Chunjee's and teadrinker's one, your function modifies the user input - compare:

Code: Select all

myArr := ["Howard", "Robin", "Fred", "Gary", "Ronnie"]
ranArr := RandomizeArray(myArr)

for k, v in myArr, out := ""
	out .= v . A_Space
MsgBox, % RTrim(out)
for k, v in ranArr, out := ""
	out .= v . A_Space
MsgBox, % RTrim(out)
return

RandomizeArray(arr) {
	local
	clone := arr.clone(), count := clone.count()
	, (newArr:=[]).setCapacity(count), index := 0
	Loop {
		Random, rand, 1, % count
		newArr[++index] := clone.removeAt(rand)
	} until !(--count)
return newArr
}

Thanks for reading

---

@Helgef

Very nice to see that the destiny of AutoHotkey and this community can still rely on your generosity and talent! Thank you very much for your invaluable work!

---

A_AhkUser

[teadrinker]

it is preferable in this case to handle a list by its indexes rather than its values

Of course, the same principle can be applied to indexes as well:

Code: Select all

RandomizeArray(Arr) {
   NewArr := []
   Loop % Arr.Count()
      str .= (str ? "|" : "") . A_Index
   Sort, str, D| Random
   Loop, parse, str, |
      NewArr.Push( Arr[A_LoopField] )
   Return NewArr
}