How to Get Back the iOS 7 SDK After Upgrading to Xcode 6

iOS 8 finally launched on September 17, and with it, the public release of Xcode 6. However, after upgrading you will notice that you can no longer compile using the iOS 7.1 base SDK. This is a problem for any app that isn’t yet compatible with the iOS 8 SDK. To see what SDK’s you have installed, open the Terminal app on your Mac and enter:

An Overview of Apple’s Swift Programming Language

The jaws of iOS developers everywhere dropped with the announcement at WWDC yesterday that Apple was introducing a new programming language to eventually replace Objective-C, called Swift. The surprise wasn’t that they did it (everyone knew it had to be done), but that it happened so soon. Apple has so much institutional knowledge of Objective-C that to replace it is truly a massive sea change. The problem with Objective-C, being a 25-year old mashup of C and Smalltalk, is that is was never quite fully-baked. And it was not suited for high-performance code, causing developers to revert to C or C++ in many cases. Here are my initial thoughts and observations on how Swift compares to Objective-C and other modern languages. There’s a LOT to cover, so I just picked out the interesting bits: