> ## Documentation Index
> Fetch the complete documentation index at: https://new.docs.falkordb.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Collection Functions

> FLEX collection functions for set operations, frequency analysis, and list manipulation in Cypher queries.

FLEX collections utilities.

## Frequently Asked Questions

<AccordionGroup>
  <Accordion title="What are FLEX collection functions?">
    FLEX collection functions provide set operations and list transformations including union, intersection, shuffling, frequency counting, and zipping lists together.
  </Accordion>

  <Accordion title="How do I call a collection function?">
    Use the namespace `flex.coll.<function>()`. For example: `flex.coll.union([1,2,3], [3,4,5])` returns `[1,2,3,4,5]`.
  </Accordion>

  <Accordion title="Do collection functions modify the original list?">
    No. All FLEX collection functions return new lists and do not mutate the input values.
  </Accordion>
</AccordionGroup>