---
title: "aggregateValue(_:)"
framework: evaluations
role: symbol
role_heading: Instance Method
path: "evaluations/evaluationresult/aggregatevalue(_:)"
---

# aggregateValue(_:)

Returns the first aggregate value matching the given operation, or -1 if not found.

## Declaration

```swift
func aggregateValue(_ operation: AggregationOperation) -> Double
```

## Parameters

- `operation`: The aggregation operation to match.