---
title: "index(_:offsetBy:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/uint/words-swift.struct/index(_:offsetby:)"
---

# index(_:offsetBy:)

Returns an index that is the specified distance from the given index.

## Declaration

```swift
func index(_ i: Self.Index, offsetBy distance: Self.Index.Stride) -> Self.Index
```

## Parameters

- `i`: A valid index of the collection.
- `distance`: The distance to offset i.

## Return Value

Return Value An index offset by distance from the index i. If distance is positive, this is the same value as the result of distance calls to index(after:). If distance is negative, this is the same value as the result of abs(distance) calls to index(before:).

## Discussion

Discussion The following example obtains an index advanced four positions from an array’s starting index and then prints the element at that position. let numbers = [10, 20, 30, 40, 50] let i = numbers.index(numbers.startIndex, offsetBy: 4) print(numbers[i]) // Prints "50" The value passed as distance must not offset i beyond the bounds of the collection. note: O(1)