map.merge

Description

Performs a shallow merge of multiple maps into a new map. When keys conflict, values from later maps override earlier ones. Non-object inputs are ignored.

Syntax 

flex.map.merge(map1, map2, ...)

Parameters

| Parameter | Type | Required | Description | |———–|——|———-|————-| | map1 | map | No | First map to merge | | map2 | map | No | Second map to merge | | ... | map | No | Additional maps to merge |

Returns

Type: map (object)

A new map containing all keys and values from the input maps. Later maps override earlier ones for duplicate keys.

Examples

Example 1: Basic Merge 

WITH {a: 1, b: 2} AS map1, {b: 3, c: 4} AS map2
RETURN flex.map.merge(map1, map2) AS result

Output:

result
------------------
{a: 1, b: 3, c: 4}

(Note: b from map2 overrides b from map1)

Example 2: Merging Node Properties 

MATCH (u:User {id: 123})
WITH {role: 'admin', status: 'active'} AS defaults
RETURN flex.map.merge(defaults, properties(u)) AS userWithDefaults

Example 3: Combining Configuration 

WITH {host: 'localhost', port: 6379} AS defaults,
     {port: 7000, password: 'secret'} AS config
RETURN flex.map.merge(defaults, config) AS finalConfig

Output:

finalConfig
--------------------------------------------------
{host: 'localhost', port: 7000, password: 'secret'}

Example 4: Merging Multiple Maps 

WITH {a: 1} AS base, {b: 2} AS extra1, {c: 3} AS extra2
RETURN flex.map.merge(base, extra1, extra2) AS combined

Notes

  • Non-object inputs are silently ignored
  • Performs shallow merge (nested objects are not deeply merged)
  • Later maps take precedence for duplicate keys
  • Returns a new map; does not modify input maps
  • Useful for applying defaults, combining configuration, or merging properties

See Also