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