--- schema_version: "1" id: 9220a7124508c05cc60406400a93780f0d3ac9aea01294aad36639d5f46d600e title: JSON Class collection: legacydeveloper version: current locale: en-us portal_url: https://docs.salesforce.com/legacydeveloper/current/en-us/apexref/apex_class_System_Json.md canonical_url: https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm source_site: developer.salesforce.com content_type: documentation content_hash: 061c715177375679ea5808eff6601d535a8a4d38685087471aa387b4dea6f944 description: Contains methods for serializing Apex objects into JSON format and deserializing JSON content that was serialized using the serialize method in this class.Returns a new JSON generator.Returns a new JSON parser.Deserializes the specified JSON string into an Apex object of the specified type.Deserializes the specified JSON string into an Apex object of the specified type.Deserializes the specified JSON string into collections of primitive data types.Serializes Apex objects into JSON content.Suppresses null values when serializing Apex objects into JSON content.Serializes Apex objects into JSON content and generates indented content using the pretty-print format.Suppresses null values when serializing Apex objects into JSON content and generates indented content using the pretty-print format. --- # JSON Class Contains methods for serializing Apex objects into JSON format and deserializing JSON content that was serialized using the serialize method in this class. ## Namespace [System](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_namespace_System.htm "The System namespace provides classes and methods for core Apex functionality.") ## Usage Use the methods in the System.JSON class to perform round-trip JSON serialization and deserialization of Apex objects. #### See Also - [_Apex Developer Guide_: Roundtrip Serialization and Deserialization](https://developer.salesforce.com/docs/atlas.en-us.264.0.apexcode.meta/apexcode/apex_json_json.htm "Apex Developer Guide: Roundtrip Serialization and Deserialization - HTML (New Window)") ## JSON Methods The following are methods for JSON. All methods are static. - **[createGenerator(prettyPrint)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#apex_System_Json_createGenerator)** Returns a new JSON generator. - **[createParser(jsonString)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#apex_System_Json_createParser)** Returns a new JSON parser. - **[deserialize(jsonString, apexType)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#apex_System_Json_deserialize)** Deserializes the specified JSON string into an Apex object of the specified type. - **[deserializeStrict(jsonString, apexType)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#apex_System_Json_deserializeStrict)** Deserializes the specified JSON string into an Apex object of the specified type. - **[deserializeUntyped(jsonString)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#apex_System_Json_deserializeUntyped)** Deserializes the specified JSON string into collections of primitive data types. - **[serialize(objectToSerialize)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#apex_System_Json_serialize)** Serializes Apex objects into JSON content. - **[serialize(objectToSerialize, suppressApexObjectNulls)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#unique_1038195925)** Suppresses null values when serializing Apex objects into JSON content. - **[serializePretty(objectToSerialize)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#apex_System_Json_serializePretty)** Serializes Apex objects into JSON content and generates indented content using the pretty-print format. - **[serializePretty(objectToSerialize, suppressApexObjectNulls)](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_Json.htm#unique_1078507453)** Suppresses null values when serializing Apex objects into JSON content and generates indented content using the pretty-print format. ### createGenerator(prettyPrint) Returns a new JSON generator. #### Signature public static System.JSONGenerator createGenerator(Boolean prettyPrint) #### Parameters - **prettyPrint**: Type: [Boolean](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_boolean.htm#apex_methods_system_boolean "Contains methods for the Boolean primitive data type.") Determines whether the JSON generator creates JSON content in pretty-print format with the content indented. Set to true to create indented content. #### Return Value Type: [System.JSONGenerator](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_JsonGenerator.htm#apex_class_System_JsonGenerator "Contains methods used to serialize objects into JSON content using the standard JSON encoding.") ### createParser(jsonString) Returns a new JSON parser. #### Signature public static System.JSONParser createParser(String jsonString) #### Parameters - **jsonString**: Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.") The JSON content to parse. #### Return Value Type: [System.JSONParser](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_class_System_JsonParser.htm#apex_class_System_JsonParser "Represents a parser for JSON-encoded content.") ### deserialize(jsonString, apexType) Deserializes the specified JSON string into an Apex object of the specified type. #### Signature public static Object deserialize(String jsonString, System.Type apexType) #### Parameters - **jsonString**: Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.") The JSON content to deserialize. - **apexType**: Type: [System.Type](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_type.htm#apex_methods_system_type "Contains methods for getting the Apex type that corresponds to an Apex class and for instantiating new types.") The Apex type of the object that this method creates after deserializing the JSON content. #### Return Value Type: Object #### Usage If the JSON content contains attributes not present in the System.Type argument, such as a missing field or object, deserialization fails in some circumstances. When deserializing JSON content into a custom object or an sObject using Salesforce API version 34.0 or earlier, this method throws a runtime exception when passed extraneous attributes. When deserializing JSON content into an Apex class in any API version, or into an object in API version 35.0 or later, no exception is thrown. When no exception is thrown, this method ignores extraneous attributes and parses the rest of the JSON content. #### Example The following example deserializes a Decimal value. Decimal n = (Decimal)JSON.deserialize( '100.1', Decimal.class); Assert.areEqual(n, 100.1); ### deserializeStrict(jsonString, apexType) Deserializes the specified JSON string into an Apex object of the specified type. #### Signature public static Object deserializeStrict(String jsonString, System.Type apexType) #### Parameters - **jsonString**: Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.") The JSON content to deserialize. - **apexType**: Type: [System.Type](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_type.htm#apex_methods_system_type "Contains methods for getting the Apex type that corresponds to an Apex class and for instantiating new types.") The Apex type of the object that this method creates after deserializing the JSON content. #### Return Value Type: Object #### Usage All attributes in the JSON string must be present in the specified type. If the JSON content contains attributes not present in the System.Type argument, such as a missing field or object, deserialization fails in some circumstances. When deserializing JSON content with extraneous attributes into an Apex class, this method throws an exception in all API versions. However, no exception is thrown when you use this method to deserialize JSON content into a custom object or an sObject. #### Example The following example defines the Car class, a user-defined type. public with sharing class Car { public String make; public String year; } The parse method in this class deserializes a JSON string into a Car object and verifies the deserialized values. public with sharing class CarJsonParser { public void parse() { Car c = (Car)JSON.deserializeStrict( '{"make":"SFDC","year":"2020"}', Car.class); Assert.areEqual('SFDC', c.make); Assert.areEqual('2020', c.year); } } ### deserializeUntyped(jsonString) Deserializes the specified JSON string into collections of primitive data types. #### Signature public static Object deserializeUntyped(String jsonString) #### Parameters - **jsonString**: Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.") The JSON content to deserialize. #### Return Value Type: Object #### Example The following example deserializes a JSON representation of an appliance object into a map that contains primitive data types and further collections of primitive types. It then verifies the deserialized values. String jsonInput = '{\\n' + ' "description" :"An appliance",\\n' + ' "accessories" : \[ "powerCord", ' + '{ "right":"door handle1", ' + '"left":"door handle2" } \],\\n' + ' "dimensions" : ' + '{ "height" : 5.5 , ' + '"width" : 3.0 , ' + '"depth" : 2.2 },\\n' + ' "type" : null,\\n' + ' "inventory" : 2000,\\n' + ' "price" : 1023.45,\\n' + ' "isShipped" : true,\\n' + ' "modelNumber" : "123"\\n' + '}'; Map m = (Map) JSON.deserializeUntyped(jsonInput); Assert.areEqual( 'An appliance', m.get('description')); List a = (List)m.get('accessories'); Assert.areEqual('powerCord', a\[0\]); Map a2 = (Map)a\[1\]; Assert.areEqual( 'door handle1', a2.get('right')); Assert.areEqual( 'door handle2', a2.get('left')); Map dim = (Map)m.get('dimensions'); Assert.areEqual( 5.5, dim.get('height')); Assert.areEqual( 3.0, dim.get('width')); Assert.areEqual( 2.2, dim.get('depth')); Assert.isNull(m.get('type')); Assert.areEqual( 2000, m.get('inventory')); Assert.areEqual( 1023.45, m.get('price')); Assert.isTrue((Boolean)m.get('isShipped')); Assert.areEqual( '123', m.get('modelNumber')); ### serialize(objectToSerialize) Serializes Apex objects into JSON content. #### Signature public static String serialize(Object objectToSerialize) #### Parameters - **objectToSerialize**: Type: Object The Apex object to serialize. #### Return Value Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.") #### Example The following example serializes a new Datetime value. Datetime dt = Datetime.newInstance( Date.newInstance( 2011, 3, 22), Time.newInstance( 1, 15, 18, 0)); String str = JSON.serialize(dt); Assert.areEqual( '"2011-03-22T08:15:18.000Z"', str); ### serialize(objectToSerialize, suppressApexObjectNulls) Suppresses null values when serializing Apex objects into JSON content. #### Signature public static String serialize(Object objectToSerialize, Boolean suppressApexObjectNulls) #### Parameters - **objectToSerialize**: Type: Object The Apex object to serialize. - **suppressApexObjectNulls**: Type: [Boolean](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_boolean.htm#apex_methods_system_boolean "Contains methods for the Boolean primitive data type.") If true, remove null values before serializing the JSON object. ![Note](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/images/icon_note.png) #### Note This parameter doesn’t apply to sObjects retrieved via SOQL. #### Return Value Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.") #### Usage This method allows you to specify whether to suppress null values when serializing Apex objects into JSON content. ### serializePretty(objectToSerialize) Serializes Apex objects into JSON content and generates indented content using the pretty-print format. #### Signature public static String serializePretty(Object objectToSerialize) #### Parameters - **objectToSerialize**: Type: Object The Apex object to serialize. #### Return Value Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.") ### serializePretty(objectToSerialize, suppressApexObjectNulls) Suppresses null values when serializing Apex objects into JSON content and generates indented content using the pretty-print format. #### Signature public static String serializePretty(Object objectToSerialize, Boolean suppressApexObjectNulls) #### Parameters - **objectToSerialize**: Type: Object The Apex object to serialize. - **suppressApexObjectNulls**: Type: [Boolean](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_boolean.htm#apex_methods_system_boolean "Contains methods for the Boolean primitive data type.") If true, remove null values before serializing the JSON object. ![Note](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/images/icon_note.png) #### Note This parameter doesn’t apply to sObjects retrieved via SOQL. #### Return Value Type: [String](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_methods_system_string.htm#apex_methods_system_string "Contains methods for the String primitive data type.")