---
title: startIndex
framework: swift
role: symbol
role_heading: Instance Property
path: swift/lazyfiltersequence/startindex
---

# startIndex

The position of the first element in a non-empty collection.

## Declaration

```swift
var startIndex: LazyFilterSequence<Base>.Index { get }
```

## Discussion

Discussion In an empty collection, startIndex == endIndex. note: O(n), where n is the ratio between unfiltered and filtered collection counts.