# init(type:) Initializes a document of a specified type. ``` convenience init(type typeName: String) throws ``` ## Parameters `typeName` The string that identifies the document type. ## Return Value The initialized `NSDocument` object, or, if the document could not be created, `nil`. ## Discussion The default implementation of this method just invokes `[self init]` and `[self setFileType:typeName]`. You can override this method to perform initialization that must be done when creating new documents but should not be done when opening existing documents. Your override should typically invoke `super`, or at least it must invoke [`init()`](/documentation/AppKit/NSDocument/init()), the `NSDocument` designated initializer, to initialize the `NSDocument` private instance variables. > Handling Errors in Swift: > In Swift, this method is marked with the `throws` keyword to indicate that it throws an error in cases of failure. > > When overriding this method, use the `throw` statement to throw an `NSError`, as described in [Error Handling](https://docs.swift.org/swift-book/LanguageGuide/ErrorHandling.html) in [The Swift Programming Language](https://docs.swift.org/swift-book/) and `About Imported Cocoa Error Parameters`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)