--- schema_version: "1" id: 1e467ae3f7ba5459fbb87066cc1d2f3e2efb572cdd0ec0947b23fff54dc18879 title: mapObject collection: mulesoft version: current locale: en-us portal_url: https://docs.salesforce.com/mulesoft/current/en-us/dataweave/2.12/dw-core-functions-mapobject.md canonical_url: https://docs.mulesoft.com/dataweave/2.12/dw-core-functions-mapobject source_site: docs.mulesoft.com content_type: documentation content_hash: 11c5fbbcc048aeae2fd7906250969c511bf8fe374bebc792c364d8485712788f description: MuleSoft Documentation Site release: "2.12" latest: false --- --- product: DataWeave version: 2.12 --- # mapObject > For the full documentation index, see: https://docs.mulesoft.com/llms.txt ## mapObject(@StreamCapable object: { (K)?: V }, mapper: (value: V, key: K, index: Number) -> Object): Object Iterates over an object using a mapper that acts on keys, values, or indices of that object. ### Parameters

Name	Description
`object`	The object to map.
`mapper`	Expression or selector that provides the `key`, `value`, or `index` used for mapping the specified object into an output object.

### Example This example iterates over the input `{ "a":"b","c":"d"}` and uses the anonymous mapper function (`(value,key,index) → { (index) : { (value):key} }`) to invert the keys and values in each specified object and to return the indices of the objects as keys. The mapper uses named parameters to identify the keys, values, and indices of the input object. Note that you can write the same expression using anonymous parameters, like this: `{"a":"b","c":"d"} mapObject { ($$$) : { ($):$$} }` #### Source ```DataWeave %dw 2.0 output application/json --- {"a":"b","c":"d"} mapObject (value,key,index) -> { (index) : { (value):key} } ``` #### Output ```JSON { "0": { "b": "a" }, "1": { "d": "c" } } ``` ### Example This example increases each price by 5 and formats the numbers to always include 2 decimals. #### Source ```DataWeave %dw 2.0 output application/xml --- { prices: payload.prices mapObject (value, key) -> { (key): (value + 5) as Number {format: "##.00"} } } ``` #### Input ```XML 9.99 53 398.99 ``` #### Output ```XML 14.99 58.00 403.99 ``` ## mapObject(value: Null, mapper: (value: Nothing, key: Nothing, index: Nothing) -> Any): Null Helper function that enables `mapObject` to work with a `null` value. ### Example Using the previous example, you can test that if the input of the `mapObject` is `null`, the output result is `null` as well. In XML `null` values are written as empty tags. You can change these values by using the writer property `writeNilOnNull=true`. #### Input ```XML ``` #### Output ```XML ```