# Friday Q&A 2017-08-25: Swift Error Handling Implementation

DevFeed: [Friday Q&A 2017-08-25: Swift Error Handling Implementation](<https://devfeed.tech/articles/friday-q-a-2017-08-25-swift-error-handling-implementation-30621.md>)

Original publisher: [Read original article](<http://www.mikeash.com/pyblog/friday-qa-2017-08-25-swift-error-handling-implementation.html>)

Author: Mike Ash

Published: 2017-08-25T13:13:00Z

Content type: article

Language: en

Sources: [Mike Ash](<https://devfeed.tech/sources/mike-ash.md>)

Topics: [Swift](<https://devfeed.tech/topics/swift.md>), [Error Handling](<https://devfeed.tech/topics/error-handling.md>), [Compiler](<https://devfeed.tech/topics/compiler.md>), [exceptions](<https://devfeed.tech/topics/exceptions.md>)

Tags: [assembly](<https://devfeed.tech/tags/assembly.md>), [compiler](<https://devfeed.tech/tags/compiler.md>), [error-handling](<https://devfeed.tech/tags/error-handling.md>), [exceptions](<https://devfeed.tech/tags/exceptions.md>), [objective-c](<https://devfeed.tech/tags/objective-c.md>), [swift](<https://devfeed.tech/tags/swift.md>)

## AI overview

This article examines how Swift error handling works internally. It first reviews throwing functions, error propagation, and handlers, then explains the implementation differences between Swift 3 and Swift 4, including hidden error parameters and a dedicated register for error returns.

## Source excerpt

Swift's error handling is a unique feature of the language. It looks a lot like exceptions in other languages, but the syntax is not quite the same, and it doesn't quite work the same either. Today I'm going to take a look at how Swift errors work on the inside. (Read More)