# Swift Type Constrained Extensions: Express Yourself

DevFeed: [Swift Type Constrained Extensions: Express Yourself](<https://devfeed.tech/articles/swift-type-constrained-extensions-express-yourself-37509.md>)

Original publisher: [Read original article](<https://www.cimgf.com/2015/12/14/swift-type-constrained-extensions-express-yourself/>)

Author: Matt Long

Published: 2015-12-14T18:19:55Z

Content type: tutorial

Language: en

Sources: [Cocoa Is My Girlfriend](<https://devfeed.tech/sources/cocoa-is-my-girlfriend.md>)

Topics: [Swift](<https://devfeed.tech/topics/swift.md>), [Objective-C](<https://devfeed.tech/topics/objective-c.md>), [Code](<https://devfeed.tech/topics/code.md>), [Mobile](<https://devfeed.tech/topics/mobile.md>), [JSON](<https://devfeed.tech/topics/json.md>)

Tags: [code](<https://devfeed.tech/tags/code.md>), [coding-practice](<https://devfeed.tech/tags/coding-practice.md>), [fetch](<https://devfeed.tech/tags/fetch.md>), [intermediate](<https://devfeed.tech/tags/intermediate.md>), [json](<https://devfeed.tech/tags/json.md>), [mobile](<https://devfeed.tech/tags/mobile.md>), [objective-c](<https://devfeed.tech/tags/objective-c.md>), [playgrounds](<https://devfeed.tech/tags/playgrounds.md>), [swift](<https://devfeed.tech/tags/swift.md>), [type](<https://devfeed.tech/tags/type.md>), [type-safety](<https://devfeed.tech/tags/type-safety.md>)

## AI overview

This tutorial explains Swift type-constrained extensions, comparing them with Objective-C categories and showing how they can provide type-safe functions and app-specific functionality for arrays and JSON-derived data.

## Source excerpt

I admit it. I was pretty down when Swift was announced. I appreciated the finer points of the reasons for it, however, they weren't convincing-at least not to me-not at first. I denied that it was actually "expressive" as the overall community was referring to it, however, that was before version 2. It's at the [...]