serializeJSON

Converts a ColdFusion variable into a JSON (JavaScript Object Notation) string.

serializeJSON(var[, serializeQueryByColumns[, useSecureJSONPrefix[, useCustomSerializer]]]) → returns string

Member Function Syntax

someVar.toJSON([serializeQueryByColumns[, useSecureJSONPrefix[, useCustomSerializer]]])

Argument Reference

var variableName
Required

A ColdFusion variable.

serializeQueryByColumns boolean
Default: `false`

A Boolean value that specifies how to serialize ColdFusion queries.

useSecureJSONPrefix boolean
Default: `false`

CF 11+ When Prefix Serialized JSON is enabled in the ColdFusion Administrator, then by default this function inserts the secure JSON prefix at the beginning of the JSON.

useCustomSerializer boolean
Default: `true`

CF 11+ Use custom serializer if defined. See: https://helpx.adobe.com/coldfusion/developing-applications/changes-in-coldfusion/restful-web-services-in-coldfusion.html

Compatibility

ColdFusion:

Version 8+ CF11+ Added Application.cfc setting this.serialization.preserveCaseForStructKey which defaults to true, also added useCustomSerializer argument. Member syntax added for CF2016+.

Lucee:

Member syntax added for Lucee5.3.8+

Links more information about serializeJSON

JSON Overview - Overview of the JSON spec.
JSONUtil.cfc - A CFC that provides JSON serialization and deserialization. It is written in CFML so it works on versions prior to CF8. It may be useful if you are experiencing automatic type conversion issues with the built-in serializeJSON function.

Examples
Sample code invoking the serializeJSON function

Serialize a Struct

Serialize a CF Struct into a JSON representation

person = {name="Pete Freitag", company="Foundeo"};
writeOutput( serializeJSON(person) );

Expected Result: {"COMPANY":"Foundeo","NAME":"Pete Freitag"}

Serialize a Struct with Member Syntax

Serialize a CF Struct into a JSON representation using toJSON

person = {name="Pete Freitag", company="Foundeo"};
writeOutput( person.toJSON() );

Expected Result: {"COMPANY":"Foundeo","NAME":"Pete Freitag"}

Lower Case Keys

Same as above but they variable names are case-sensitive by quoting them.

person = {"name"="Pete Freitag", "company"="Foundeo"};
writeOutput( serializeJSON(person) );

Expected Result: {"company":"Foundeo","name":"Pete Freitag"}

Adobe ColdFusion may incorrectly serializes some strings if they can be automatically converted into other types, like numbers or booleans. One workaround is to use a CFC with cfproperty to specify types. Another workaround is to prepend Chr(2) to the value and it will be forced to a string, however that is an unofficial / undocumented workaround.

person = { "phone"="123456789", "firstname"="no","lastname"="yes" };
writeOutput( serializeJson(person) );

Expected Result: {"phone":123456789,"firstname":false,"lastname":true}

Using setMetadata to force types

As of CF 2016.0.2+ (update 2) you can call setMetadata() as a member function on a struct to force a type

myStruct = {"zip"="00123"};
myStruct.setMetadata( { "zip": "string" } );
writeOutput(serializeJSON(myStruct));

Expected Result: {"zip":"00123"}