Adds or modifies an element in JSON data specified by an object name, an array index, or a path.


JSONSetElement ( json ; keyOrIndexOrPath ; value ; type )


json - any text expression or field that contains a JSON object or array.

keyOrIndexOrPath - any text expression or field that specifies a JSON object name (key), an array index, or a path. See Working with the JSON functions.

value - any expression or field that contains a number, text, or JSON data.

type - a numeric value that specifies the type of data to be set (see below).

Data type returned 


Originated in version 



This function returns json with value set at the specified keyOrIndexOrPath. If the json parameter is blank (""), this function adds value to a JSON object (in braces { }), unless the first part of the keyOrIndexOrPath parameter starts with a "[" character. In that case, this function adds value to a JSON array (in brackets [ ]).

For the type parameter, use one of the following values. When value is added into json, the type parameter specifies whether to convert value to a specific JSON type or to insert value without changing the type.

type parameter1

Input type for value parameter

Output type

JSONString (1)

FileMaker text

JSON string (" ")

JSONNumber (2)

FileMaker number

JSON number

JSONObject (3)

JSON object

JSON object ( { } )

JSONArray (4)

JSON array

JSON array ( [ ] )

JSONBoolean (5)

FileMaker value or JSON Boolean value

JSON Boolean

JSONNull (6)

Type is ignored

JSON null

JSONRaw (0)

JSON element

JSON element (or JSON string, if value is not valid JSON)

  1. You can specify type using either the named constant or the numeric value shown in parentheses—for example, JSONString or 1—without quotes.

For JSONBoolean, if value is true or a non-zero number, it is treated as true; if value is false or zero, it is treated as false. Otherwise, whether value is true or false is determined in the same way as the test parameter is in the If function.

For JSONRaw, the JSON parser processes value to determine whether it uses valid JSON syntax. If value is valid JSON, the parsed result is used in this function's returned value without converting any elements to JSON data types. Any characters after the first JSON element in value are ignored—for example, if value is "4,2", only "4" will be inserted, because a comma is the separator between elements in JSON syntax. If value is not valid JSON, value is converted to a JSON string in the returned value.

You can set multiple elements by providing an additional set of keyOrIndexOrPath, value, and type parameters in brackets [ ] for each element. The following syntax sets N elements at once:

JSONSetElement ( json ; 
   [ keyOrIndexOrPath1 ; value1 ; type1 ] ; 
   [ keyOrIndexOrPath2 ; value2 ; type2 ] ; 
   [ keyOrIndexOrPathN ; valueN ; typeN ]

Example 1 

Adds a key and its value to the root of a JSON object.

JSONSetElement ( "{ \"a\" : 11 }" ; "b" ; 22.23 ; JSONNumber ) returns {"a":11,"b":22.23}.

Example 2 

Creates an array, adds one element (a JSON object) using the "[+]" syntax, then uses the "[:]" syntax to reference that element as the last element in the array in order to add another key-value pair to the object.

JSONSetElement( "[]"; 
    ["[+].a", 5, JSONNumber] ; 
    ["[:].b", 6, JSONNumber]

Returns [{"a":5,"b":6}].

Example 3 

Adds a JSON object as an element of another JSON object. If the $$JSON variable is set to

    "a" : {
        "id" : 12,
        "lnk" : 34


JSONFormatElements ( 
   JSONSetElement ( $$JSON ; "b" ; "{ \"id\" : 14, \"lnk\" : 73 } " ; 


        "id" : 12,
        "lnk" : 34
        "id" : 14,
        "lnk" : 73

Example 4 

In the Example JSON data stored in the $$JSON variable, changes the values of the "special" and "stock" keys in the first "product" element in the array.

JSONFormatElements ( 
   JSONSetElement ( $$JSON ; 
   [ "bakery.product[0].special" ; 0 ; JSONBoolean ] ; 
   [ "bakery.product[0].stock" ; 0 ; JSONNumber ] 

returns the same data as in $$JSON but with the first element of the "product" array changed to

    "category" : "Breads",
    "id" : "FB1",
    "name" : "Donuts",
    "price" : 1.99,
    "special" : false,
    "stock" : 0