apoc.map.get

Function

apoc.map.get(map MAP<STRING, ANY>, key STRING, value ANY, fail BOOLEAN) - returns a value for the given key. If the given key does not exist, or lacks a default value, this function will throw an exception.

Signature

apoc.map.get(map :: MAP, key :: STRING, value = null :: ANY, fail = true :: BOOLEAN) :: ANY

Input parameters

Name Type Default

map

MAP

null

key

STRING

null

value

ANY

null

fail

BOOLEAN

true

Usage Examples

The following throws an exception when attempting to look up missing key missingKey with no default value:

WITH {name:"Cristiano Ronaldo",country:"Portugal",dob:date("1985-02-05")} AS map
RETURN apoc.map.get(map, "missingKey") AS output;
Table 1. Results
Output

Neo.ClientError.Procedure.ProcedureCallFailed: Failed to invoke function apoc.map.get: Caused by: java.lang.IllegalArgumentException: Key missingKey is not of one of the existing keys [country, dob, name]

The following returns default value defaultValue when attempting to look up missing key missingKey:

WITH {name:"Cristiano Ronaldo", country:"Portugal", dob:date("1985-02-05")} AS map
RETURN apoc.map.get(map, "missingKey", "defaultValue") AS output;
Table 2. Results
Output

"defaultValue"