coll.shuffle

Description

Randomly shuffles the elements of a list using the Fisher-Yates algorithm. Returns a new list with elements in random order without modifying the original.

Syntax

flex.coll.shuffle(list)

Parameters

Parameter	Type	Required	Description
`list`	list	Yes	The list to shuffle

Returns

Type: list

A new list containing the same elements in a randomized order. Returns an empty list if input is not an array.

Examples

Example 1: Basic Shuffle

WITH [1, 2, 3, 4, 5] AS numbers
RETURN flex.coll.shuffle(numbers) AS shuffled

Output: (example, actual order will vary)

shuffled
-----------
[3, 1, 5, 2, 4]

Example 2: Random Sample Selection

MATCH (q:Question)
WITH collect(q) AS allQuestions
WITH flex.coll.shuffle(allQuestions) AS randomized
RETURN randomized[0..10] AS quizQuestions

Example 3: Randomizing Recommendations

MATCH (u:User {id: $userId})-[:LIKES]->(p:Product)
MATCH (p)-[:SIMILAR_TO]->(rec:Product)
WITH collect(DISTINCT rec) AS recommendations
RETURN flex.coll.shuffle(recommendations)[0..5] AS randomRecs

Example 4: Random Team Assignment

MATCH (p:Player)
WITH collect(p.name) AS players
WITH flex.coll.shuffle(players) AS shuffled
RETURN shuffled[0..5] AS team1, shuffled[5..10] AS team2

Notes

Returns empty list if input is not an array or is null
Uses the Fisher-Yates shuffle algorithm for uniform random distribution
Creates a new list; does not modify the original
Each element appears exactly once in the result
Order is truly random on each execution