---
title: "init(_:)"
framework: usdkit
role: symbol
role_heading: Initializer
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, macOS 27.0+, tvOS 27.0+, visionOS 27.0+]
path: "usdkit/usdarray/init(_:)-1re5y"
---

# init(_:)

Creates an array containing the elements of s.

## Declaration

```swift
init(_ s: some Sequence<Element>)
```

## Discussion

Discussion The backing C++ storage is reserved up front from the sequence’s underestimatedCount, so the common case allocates once rather than reallocating repeatedly while appending. underestimatedCount is exact and O(1) for collections such as Array; for sequences whose count isn’t known it is a lower bound (possibly zero) used purely as a reservation hint, which avoids a second traversal just to count.