---
title: "swapAt(_:_:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/mutablecollection/swapat(_:_:)"
---

# swapAt(_:_:)

Exchanges the values at the specified indices of the collection.

## Declaration

```swift
mutating func swapAt(_ i: Self.Index, _ j: Self.Index)
```

## Parameters

- `i`: The index of the first value to swap.
- `j`: The index of the second value to swap.

## Discussion

Discussion Both parameters must be valid indices of the collection and not equal to endIndex. Passing the same index as both i and j has no effect. note: O(1)