# preflight() Returns a Boolean value indicating whether the bundle’s executable code could be loaded successfully. ``` func preflight() throws ``` ## Discussion This method does not actually load the bundle’s executable code. Instead, it performs several checks to see if the code could be loaded and with one exception returns the same errors that would occur during an actual load operation. The one exception is the `NSExecutableLinkError` error, which requires the actual loading of the code to verify link errors. For a list of possible load errors, see the discussion for the [`loadAndReturnError()`](/documentation/Foundation/Bundle/loadAndReturnError()) method. > Handling Errors in Swift: > In Swift, this method returns `Void` and is marked with the `throws` keyword to indicate that it throws an error in cases of failure. > > You call this method in a `try` expression and handle any errors in the `catch` clauses of a `do` statement, 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)