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# Resource: Items

# Type: WixDataAggregatePipelineExpressions

# Action: add

# Link: https://dev.wix.com/docs/sdk/data-items-sdk/data/items/wix-data-aggregate-pipeline-expressions/add.md

## Description: Adds the specified expressions.

The `add()` method configures the aggregation pipeline to add the values of the specified expressions.

## Schema:

```json
 Method: add(expressions)
 Description: Adds the specified expressions.  The `add()` method configures the aggregation pipeline to add the values of the specified expressions.
 Method parameters:
   param name:  expressions | type: Array<Expression> | description:  Expressions to add together. All expressions must resolve to numbers. Learn more about using [expressions in aggregation pipelines](https://dev.wix.com/docs/sdk/backend-modules/data/items/wix-data-aggregate-pipeline-expressions/introduction.md). 
 Return type: REFERENCE<AddExpression>

```