Learn how to remove the previous card from your phone.Make sure the phone is switched off. 1. At the top corner of your phone, put the nail of your index finger in the seam between the screenframe and the back cover. Press the middle of the back cover, and bend the cover to loosen the tophooks.
While the Objective-C traditionally had no garbage collection, with the release of OS X 10.5 in 2007 Apple introduced garbage collection for Objective-C 2.0, using an in-house developed runtime collector.
What it is: Objective-C is a general-purpose, object-oriented programming language used by the Apple operating system. It powers Apple's OS X and iOS, as well as its APIs, and can be used to create iPhone apps, which has generated a huge demand for this once-outmoded programming language. Where to learn it: Udemy, Lynda.com, Mac Developer Library, Cocoa Dev Central, Mobile Tuts+.