--- schema_version: "1" id: e834637e2ea35b22e0fddf09f28c6e6466fba75644e8ba5f9588e77f6370f001 title: Set Variable () collection: mulesoft version: current locale: en-us portal_url: https://docs.salesforce.com/mulesoft/current/en-us/anypoint-code-builder/acb-component-set-variable.md canonical_url: https://docs.mulesoft.com/anypoint-code-builder/acb-component-set-variable source_site: docs.mulesoft.com content_type: documentation content_hash: 86b80b4f6d66ac6c342436af38140d9233b48d68d9e5780aacb628531f9fea94 description: MuleSoft Documentation Site latest: true --- --- product: Anypoint Code Builder version: master --- # Set Variable () > For the full documentation index, see: https://docs.mulesoft.com/llms.txt Creates or updates a [Mule variable](https://docs.mulesoft.com/mule-runtime/latest/about-mule-variables) to store values for use within the flow of a Mule app. A Mule variable is part of the [Mule event](https://docs.mulesoft.com/mule-runtime/latest/about-mule-event). You can store simple literal values such as strings or messages, message payloads, or attribute objects. For example, you might store the original payload of a message (before it is processed) so you can use it later in the flow or within an error handler. Don’t use Set Variable for complex expressions or transformations. Instead, use the component for simple operations, such as selections, and use the Transform component for complex scenarios. ## Component XML This component supports the following XML structure: ```xml ``` Set Variable (``) attributes are configurable through the UI and XML.
Attribute NameAttribute XMLDescription

Set variable (default)

doc:name

Editable name for the component to display in the canvas.

N/A

doc:id

Automatically generated identifier for the component.

Value

value

Value for the variable, which can be a string or a DataWeave expression. For an example that uses an expression, see Use Dynamic Writer Properties. This attribute is required.

Variable name

variableName

Name of the variable, which can be a string or a DataWeave expression. Variable names are must include only numbers, characters, and underscores. This attribute is required.

Encoding

encoding

Encoding of the payload that this component outputs.

Mime type

mimeType

MIME type of the payload that this component outputs. For more information, see Using Reader and Writer Properties.

Parameters

N/A

Appends a key-value pair for a reader property to the value of the outputMimeType attribute. Multiple key-value pairs are allowed. Reader properties are specific to the MIME type. For example, see the JSON reader properties for application/json. To find other reader properties, navigate to a supported format from the DataWeave format documentation, and see Using Reader and Writer Properties.

## Accessing Variables in Other Event Processors Set Variable sets a variable in the current Mule event, and the variables then travel with the Mule event to downstream event processors. You can access any variable with DataWeave using `vars`. For example, you can access a variable named _lastMessage_ with `vars.lastMessage`. You can set variables in a Transform component, and also many connectors and event processors have a Target variable that you can set. ## Examples ### Example: Setting a Variable With a String Value The following example assigns a String value to a variable: ```xml ``` ### Example: Setting the Result of a DataWeave Expression as a Variable The following example assigns the result of a DataWeave expression to a variable: ```xml ``` ### Example: Setting a Variable to the Message Payload The following example assigns the message payload to a variable: ```xml ``` ### Example: Setting a Variable to the Message Attributes The following example assigns the message attributes to a variable: ```xml ``` ### Example: Setting a Variable With a Map Value The following example assigns a map value to a variable: ```xml ``` ### Example: Setting a Variable to a Java Object The following example assigns a Java object to a variable by using a DataWeave script: ```xml ``` ## See Also - [Transform Component](https://docs.mulesoft.com/anypoint-code-builder/acb-component-transform) - [Variables in Mule Events](https://docs.mulesoft.com/mule-runtime/latest/about-mule-variables) - [Enrich Data with Target Variables](https://docs.mulesoft.com/mule-runtime/latest/target-variables)