---
title: "init(_:)"
framework: applearchive
role: symbol
role_heading: Initializer
path: "applearchive/archiveheader/fieldkey-swift.struct/init(_:)"
---

# init(_:)

Creates a new field key from the key you specify.

## Declaration

```swift
init(_ key: String)
```

## Parameters

- `key`: The string for the key that must have a length of 3 characters that are in the range 32...127.