---
title: underestimatedCount
framework: swift
role: symbol
role_heading: Instance Property
path: swift/enumeratedsequence/underestimatedcount
---

# underestimatedCount

A value less than or equal to the number of elements in the sequence, calculated nondestructively.

## Declaration

```swift
var underestimatedCount: Int { get }
```

## Discussion

Discussion The default implementation returns 0. If you provide your own implementation, make sure to compute the value nondestructively. note: O(1), except if the sequence also conforms to Collection. In this case, see the documentation of Collection.underestimatedCount.