IOS 9, Swift 2.0, Xcode and testing

Question

I plan to learn how to develop applications for iOS. I will most likely be learning Objective-C just now and would like to develop some current iOS apps.

Now, with the launch of Swift 2.0, will Objective-C applications run on iOS9? Also, is it possible to test the Objective-C application on your phone as indicated here? https://developer.apple.com/xcode/ Or is this tool available only for applications written in Swift?

Does Swift Allow All That Objective-C Does?

Any further recommendations or directions regarding what I should know before entering the course will be appreciated to help me better judge.

Answer 1

Swift is still the second language. All Cocoa frameworks are written in C or Obj-C (possibly new ones in iOS 9 are written in Swift).

The language in which the application is written does not matter, the code is compiled into the same machine code, so yes, Obj-C applications will continue to work, and many developers will not worry about Swift. Applications that have already been written should not be rewritten in Swift (with some exceptions).

Swift will not allow you to do absolutely everything that Obj-C does, but it will allow you to do almost everything, and the code will probably be more reliable, given that Swift is a more modern language with stronger typing than Obj-C, If you're a beginner, you probably won't find a problem use case.