map.fromPairs

Description

Converts a list of key-value pairs into a map. Each pair should be a two-element array [key, value].

Syntax 

flex.map.fromPairs(pairs)

Parameters

| Parameter | Type | Required | Description | |———–|——|———-|————-| | pairs | list | Yes | A list of two-element arrays, each containing [key, value] |

Returns

Type: map (object)

A map where each key-value pair from the input list becomes a property. Returns an empty map if input is not an array.

Examples

Example 1: Basic Conversion 

WITH [['name', 'Alice'], ['age', 30], ['city', 'NYC']] AS pairs
RETURN flex.map.fromPairs(pairs) AS result

Output:

result
------------------------------------
{name: 'Alice', age: 30, city: 'NYC'}

Example 2: Converting Zipped Data 

WITH ['name', 'age', 'email'] AS keys,
     ['Bob', 25, 'bob@example.com'] AS values
WITH flex.coll.zip(keys, values) AS pairs
RETURN flex.map.fromPairs(pairs) AS user

Output:

user
------------------------------------------
{name: 'Bob', age: 25, email: 'bob@example.com'}

Example 3: Dynamic Property Creation 

MATCH (p:Product)
WITH collect([p.id, p.price]) AS pricePairs
RETURN flex.map.fromPairs(pricePairs) AS priceMap

Example 4: Converting Query Results to Lookup Map 

MATCH (c:Country)
WITH collect([c.code, c.name]) AS countryPairs
WITH flex.map.fromPairs(countryPairs) AS lookup
RETURN lookup['US'] AS usaName, lookup['UK'] AS ukName

Notes

  • Returns empty map if input is not an array or is null
  • Each pair must be a two-element array; invalid pairs are skipped
  • If a key is null or undefined, the pair is ignored
  • Duplicate keys result in the last value being used
  • Keys are converted to strings as map property names

See Also