---
title: "index(before:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/substring/unicodescalarview/index(before:)"
---

# index(before:)

Returns the position immediately before the given index.

## Declaration

```swift
func index(before i: Substring.UnicodeScalarView.Index) -> Substring.UnicodeScalarView.Index
```

## Parameters

- `i`: A valid index of the collection. i must be greater than startIndex.

## Return Value

Return Value The index value immediately before i.