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# Resource: Items

# Type: WixDataAggregatePipelineExpressions

# Action: concat

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

## Description: Joins multiple expressions together to create a string.

The `concat()` method configures the aggregation pipeline to join multiple expressions together to create a new string.

## Schema:

```json
 Method: concat(expressions)
 Description: Joins multiple expressions together to create a string.  The `concat()` method configures the aggregation pipeline to join multiple expressions together to create a new string.
 Method parameters:
   param name:  expressions | type: Array<Expression> | description:  Expressions to join together. All expressions must resolve to strings. 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<ConcatExpression>

```