A Beginner's Guide To Programming With Swift

Nerval's Lobster (2598977) writes Earlier this year, Apple executives unveiled Swift, which is meant to eventually replace Objective-C as the programming language of choice for Macs and iOS devices. Now that iOS 8's out, a lot of developers who build apps for Apple's platforms will likely give Swift a more intensive look. While Apple boasts that Swift makes programming easy, it'll take some time to learn how the language works. A new walkthrough by developer David Bolton shows how to build a very simple app in Swift, complete with project files (hosted on SourceForge) so you can follow along. A key takeaway: while some Swift features do make programming easier, there's definitely a learning curve here.

Comments

Swift name

[Anonymous Coward]

I thought it was talking about SWIFT the object store, part of Openstack. Apple should have called their language iSwift.

Re: Swift name

[Anonymous Coward]

Or not to be confused with the Society for Worldwide Interbank Financial Telecommunication.

Just what we needed...

[__aaclcg7560]

Another language filled with adverbs.

Re:Just what we needed...

[MightyMartian]

Another attempt by a vendor to try to lock in software development and make cross platform development incredibly difficult by introducing a new language.

Fuck, I do tire of the sociopathic tendencies of corporations.

Re:Just what we needed...

[iluvcapra]

Thank god we have Android Dalvik, where I can use my existing Java ME codebase. Oh wait.

We're going from Obj-C to Swift, this seems like a pretty lateral move from a "cross platform" perspective. I would have thought the Great Java Wars had taught everyone that true cross-platform development is a chimera that isn't worth either the vendor or developer's effort. Platform vendors compete on features -- cross platform is antithetical to competition on features.

Re:Just what we needed...

[Anonymous Coward]

...and hipsters creating new js frameworks every week

Re:Just what we needed...

[Capsaicin]

Another attempt by a vendor to try to lock in software development and make cross platform development incredibly difficult by introducing a new language.

... because writing Objective-C Apps using the Cocoa object framework is the very model of cross-platform development.

What surprises me is that it Apple until now to "make cross platform development incredibly difficult."

Re:Just what we needed...

[Pseudonym]

"We wouldn't have swallowed this at NeXT", said Ross perorally.

Re:Just what we needed...

[Anonymous Coward]

It is lateral. From most perspectives Swift is ridiculously ugly and not very interesting.

What makes Swift interesting, if at all, is its integration with the Objective-C runtime, and in particular the way it efficiently manages garbage collection and boxing of Objective-C objects using fat pointers.

Swift looks exactly like what you'd get from the the guy who invented LLVM and has more than a few clever ideas about low-level type management and compiling to machine code, but who wouldn't know good language design from a hole in the ground. He's somebody who lives and breathes C++ and assembly, and who would never bother playing around with Haskell.

I'm a full-time C programmer, but I look to functional and declarative languages for inspiration when modeling my programs. I don't see any of that having been seriously attempted with Swift. Swift is just an exercise in automating common, low-level typing patterns and workarounds from the perspective of a C, C++, or Objective-C programmer.

Re:Just what we needed...

[Anonymous Coward]

Fuck, I do tire of the sociopathic tendencies of corporations.

I do tire of all the sociopathic cynics who assume that every act by every corporation is pure evil.

Re:Just what we needed...

[Anonymous Coward]

"I would have thought the Great Java Wars had taught everyone that true cross-platform development is a chimera that isn't worth either the vendor or developer's effort."

Nonsense. 20+ years of experience for large blue chip companies, many of those years as an Architect / CTO. I have advised companies for many years to use C or Java an run them across multiple platforms. All but 1 years / a single project has been successful. Web based UIs are relatively easy cross browser unless doing extensive/low level javascript (use a decent abstraction layer) and these kinds of cross platform libraries are becoming prevalent for smartphones too, only inappropriate if doing low level / performance minded work. Most future projects will be cross platform because user now don't know/care what platform your services run on, and the economics / project deadlines mean its becoming unfeasible to develop code for each front end / platform you want to support. As a more diverse set of devices become mainstream (almost inevitable) responsive / multiplatform apps will become the norm... Not to mention the majority/normal practice of develop on windows, deploy on unix, or the more recent new developer to a company trend of what kind of box do you prefer working with we'll buy one of those for you starting rather than everyone gets a standard machine old school thinking...

Re:Just what we needed...

[Anonymous Coward]

JavaME was a purposedly limited platform to fit a certain class of old devices, the limitations have no sense in Dalvik. "Cross platform" would be a nonsense here. You are either biased or ignorant.

Re:Just what we needed...

[slashdice]

What I find interesting is the ability to create new operators. Not just overloading existing ones, but creating new ones that affect parsing -- prefix, postfix, or infix with custom precedence and associativity.

Custom operators can begin with one of the ASCII characters [list of punctuation dice considers junk characters], or one of the Unicode characters defined in the grammar below. After the first character, combining Unicode characters are also allowed. You can also define custom operators as a sequence of two or more dots (for example, ....). Although you can define custom operators that contain a question mark character (?), they canÃ(TM)t consist of a single question mark character only.

If nothing else, the javascript nee ruby nee php hipsters will give some great examples of why this is a bad idea!

Looking forward to some great fart apps written in ascii art...

Re:Just what we needed...

[irq-1]

I would have thought the Great Java Wars had taught everyone that true cross-platform development is a chimera that isn't worth either the vendor or developer's effort. Platform vendors compete on features -- cross platform is antithetical to competition on features.

Remember when people called browsers "platforms" and the websites were "applications"? 20+ years of the web has shown that cross platform works, that what counts as a platform is malleable, and that the features companies compete over, change over time. Today in mobile language is a feature in contention, but if Cordova (et al.) become popular, Apple and Google will compete over different features.

Re:Just what we needed...

[iluvcapra]

Whatever you say, AC. However, I'm totally not surprised by a C-level executive and "Architect"-with-a-capital-A extolling the virtues of Java, Web UIs and giving the old song and dance about cross-platform only being about "performance."

Most future projects will be cross platform because user now don't know/care what platform your services run on...

Application vendors desperately want the platform to be a dumb pipe that disappears in order to deliver the Pure Application Experience. Platform vendors desperately want apps to distinctively convey their platform's benefits.

Re:Just what we needed...

[iluvcapra]

From most perspectives Swift is ridiculously ugly and not very interesting.

public interface Troll {
  void post();
}
 
public class Complaint implements Troll {
  @Override
  public void post() {
      System.out.println("Swift is ridiculously ugly, especially compared to Java!");
  }
}
 
public class TrollFactory {
  public Troll getTroll(String trollType){
      if(trollType == null){
        return null;
      }
      if(trollType.equalsIgnoreCase("COMPLAINT")){
        return new Complaint();
      }
      return null;
  }
}

Re:Just what we needed...

[Anonymous Coward]

Great, because Haskell has some warts, but really they're nothing compared to the sheer annoyances that are GHC and ghci. Argh. A Haskell front end for LLVM (but not the way GHC was doing it a few years ago) would be awesomesauce.

Yeah but does it run on

[Spy Handler]

Linux? Or do I have to buy a mac.

Re:Yeah but does it run on

[Anonymous Coward]

It's only truly useful for MacOS/iOS development (as a modern replacement for ObjC), so I doubt you'd want to use it elsewhere.

learning curve?

[Anonymous Coward]

>A key takeaway: while some Swift features do make programming easier, there's definitely a learning curve here.
you don't say?! One would expect Apple had essentially done away with learning curves so that just about anyone and their uncle can write great apps in just a few minutes! Programming is so overrated, how hard can it be?

Re:learning curve?

[Anonymous Coward]

In my opinion, Swift is clearly oriented towards relative newbies and quick-out-the-door apps. Even though not strictly language issues, that it was released with real-time rendering of code while missing anything like vDSP.h or Metal goes to show where the priorities lay.

Re:learning curve?

[narcc]

They did ... once upon a time. Remember HyperCard?

I don't know why people are so desperate to believe that programming is difficult. How old were you when you (very likely on your own) learned to program? 8 or 9 years old?

I know, I know, if we give the unwashed masses simple and powerful tools they'll write bad code. The horror. Better leave it to the professionals. Surely, they never produce unmaintainable garbage...

Re:learning curve?

[Dutch Gun]

Programming is sort of like cooking. Anyone can learn the basics and make some interesting and satisfying stuff - even an eight year old can to do some rudimentary stuff. I'd even venture to say that many people can make a living at it, as there are lots of jobs that don't involve doing incredibly demanding tasks - just basic production work. But there are also top tier jobs that require extremely experienced and talented professionals with years of study under their belt. Not everyone is suited for that job, but that's fine, since there are quite a bit fewer of them anyhow.

In other words, there's nothing wrong with making tuna casserole (using Hypercard to create a simple database application), but don't try to kid yourself it's basically the same thing as creating a full course meal at a four-star restaurant (writing low-level, high-performance code in C).

And, just like there are bad chefs to have no real business being in the kitchen, there are professional programmers who shouldn't be coding until they've polished up their skills or gained some more experience. The fact that there's so much badly written code out there seems to demonstrate that programming well is rather more difficult than many would like to admit.

Re:learning curve?

[narcc]

That's delusional. I've been at this longer than a lot of users here have been alive, yet the only "complex" applications I've seen are either unnecessarily complex or complex for reasons completely unrelated to programming.

It's not like cooking at all. That's just wishful thinking.

Programming is easy. Ridiculously easy. You know this, I know this. Why hide it?

Why not produce easy tools for non-programmers to use? We use programming languages to make writing software easier, after all. Why are modern languages and tools becoming increasingly more complex? Software isn't getting more complex in general, so why are our tools? What are we afraid will happen? That we'll lose our jobs? That people won't admire us for a skill easily attainable by young children?

there's nothing wrong with making tuna casserole (using Hypercard to create a simple database application), but don't try to kid yourself it's basically the same thing as creating a full course meal at a four-star restaurant (writing low-level, high-performance code in C).

But it is! The EXACT same skills and principles apply equally in both cases. (Note: This is not the case for cooking. Your analogy breaks immediately.) The only difference is that you need to know a few additional technical details to use C effectively. That's tangential to programming, no different than something like domain specific knowledge you'd need writing programs for use in different industries.

Re:learning curve?

[Dutch Gun]

I happen to have written large-scale commercial videogames in C++ for most of my career. I've worked with lots of people, many smarter than me, and I don't recall anyone talking about how their programming work was "ridiculously easy". I'm glad everything is so simple for you, but apparently we're not all so fortunate.

Re:learning curve?

[brantondaveperson]

Well, to be fair *writing code* is pretty easy. But designing complex systems for reliability and maintainability is not. I suppose the GP believes that programming is the former, whereas I would have thought that it's more of the latter.

Re:learning curve?

[Anonymous Coward]

But it is! The EXACT same skills and principles apply equally in both cases. (Note: This is not the case for cooking. Your analogy breaks immediately.)

I think the GP's analogy is reasonably apt. Even when looking at the same basic skills used at both the low and high level, at the low level you have a lot more leeway to be sloppy. Many home cooking recipes can be cooked for varying lengths, use a variety of ingredients, and let some measurement errors go by un-noticed, still producing a solid, satisfying meal. Likewise, a lot of small programming projects can still work fine even with horrible algorithm choices because the dataset is too small for scaling to make a difference, or involve very sloppy structure to the code because there is so little maintenance needed or will just be a one-off project.

At the high level, you end up using the same basic principles, but they better be a lot more refined. In some cases you better have put some thought in to which algorithm you use and if it will scale to your problem and budget. You better structure your code cleanly so that a team of people can work together to both create and maintain it. You need to thoroughly test code before putting into production, unlike smaller projects that can just be monitored on the fly, or have results that can be eyeballed each time it runs. Just as with cooking, a lot of the high level cooking uses the same basic techniques, but with a lot more attention to the impact of each ingredient, getting the texture to actually come out interesting, and to produce a great taste that stands out.

Try asking a group of people to write some data storing program that does just a small subset of say a database, and you will get a spectrum of results from ones that barely work on a test set to ones that can handle a million times as much data and be easily to debug if there were a mistake. Just as if you ask a bunch of people to simply cook a piece of chicken in a pan, you will get a spread from tough & bland to moist & flavorful.

Re:learning curve?

[Dutch Gun]

Yeah, well, of course "writing code" is easy, just like typing coherent sentences in English is rather easy. It doesn't mean it's easy to write a novel any more than it means "programming is easy". The difficulty scales along with the scope and complexity of what you're trying to accomplish, as with most things in life.

Honestly, I was trying to exit the topic of conversation gracefully, because it didn't sound like he was open to any sort of reasonable discussion, and feels more like a trolling attempt than a conversation at this point - calling me "delusional", and implying I'm in denial, fearful of losing my job, and that a child could likely replace me at work. That doesn't seem like a conversation worth salvaging, but thanks for your reply.

Re:learning curve?

[narcc]

it didn't sound like he was open to any sort of reasonable discussion

Well, you're right about that. A "reasonable discussion" isn't possible here. Can you have a "reasonable discussion" with a creationist? Neither can I. All you can do is show them the facts. It's up to them to accept reality, just as it's up to you.

Just look at the parent here:

designing complex systems for reliability and maintainability is not

Ah, but it is! (Hell, if it's actually complex, it's not maintainable.) See, most "complex systems" are only complex because of how their designed (poorly). Yes, some things are actually complex but that's generally completely unrelated to programming (see my earlier post).

Personally, I blame the OOP craze for the dramatic increase in unnecessary complexity. We've got two generations, now, of programmers who know nothing about modularity, but believe (inexplicably) that OOP gives them modularity for free.

This shouldn't be controversial. The only explanation I have for the need to believe that programming is difficult is fear.

Re:learning curve?

[Anonymous Coward]

they're

You're welcome.

Re:learning curve?

[tehcyder]

I'd rather have a good car analogy.

Programming is like driving a car: some people are incapable of driving without killing bystanders or themselves, the majority can get by quite happily going shopping, and a few are F1 racing drivers.
Most programs, and especially most iPhone apps, are my mum going to Tesco's, not Lewis Hamilton pipping Nico Rosberg by two hundredths of a second in the final title-deciding race of the season.

Re: learning curve?

[Anonymous Coward]

Indeed, I learnt to program at 11, 12 years, that was 1984/1985. Having come a long way since, I know that writing code is not the same as writing maintainable, extensible and performant code. So it is not the programming per se that's difficult, the real challenge is managing complexity and non functional requirements. Alas, the programming language hardly matters (it does, however, affect productivity a great deal).

Re:learning curve?

[Tablizer]

Learning programming is relatively easy. Learning to write maintainable code, on the other hand, takes skill and experience.

Clerks and accountants used to do amazing things with Lotus-1-2-3 macros because Lotus cleverly leveraged what users already knew about spreadsheets into a Turing Complete set of commands. But often these users eventually got themselves into a jam, or made something that nobody else could decipher.

Slight Misunderstanding

[iluvcapra]

TFA is actually mostly a Cocoa application stack guide. Discussion of the actual distinguishing features of Swift is minimal -- in fact I think the only thing they even passingly mention is unwrapping of Optionals. Otherwise it's just "How to build an iOS app"

I read the article

[Anonymous Coward]

Thought the alert in the example said "I love Dick"...

Then I realized my mind translated Dice to Dick.

GJ Subconscious! Gold star!

Embracing the bird

[javawocky]

I have started going through the "Skip Wilson" tutorials and have found the language quite refreshing - borrowing mainly from JS / Java / Python imo. But then again anything more refreshing than my PHP day job.

Re:Embracing the bird

[goombah99]

I love his Geraldine character.

Re:Embracing the bird

[MightyMartian]

If you start with PHP, even Brainfuck looks fun and refreshing. Jesus pal, talk about damning a language with faint praise.

Re:Embracing the bird

[iluvcapra]

What are you, 60?

Re:Embracing the bird

[HiThere]

Now that's just not true. Brainfuck is worse than PHP. So, for that matter, is whitespace.

Re:Embracing the bird

[Anonymous Coward]

A+, not as bad as Hitler, would vote again.

Re:Embracing the bird

[Paradise Pete]

What are you, 60?

Don't rag on people for getting old. That kinda is the goal, isn't it?

Re:Embracing the bird

[tehcyder]

Yes, we know that. GP was exaggerating for comic effect.

Re:Embracing the bird

[terjeber]

exaggerating slightly for comic

Prerequisites

[tuppe666]

"You need a Mac that can run OS X Mavericks"

  A key takeaway:No wonder Android has more Apps(sic) than iOS after starting from behind.

Re:Prerequisites

[Anonymous Coward]

"You need a Mac that can run OS X Mavericks"

  A key takeaway:No wonder Android has more Apps(sic) than iOS after starting from behind.

Because your dev machine for this new language can't be more then 6 years old? Yeah, sure.

Re:Prerequisites

[Half-pint HAL]

"You need a Mac that can run OS X Mavericks"

A key takeaway:No wonder Android has more Apps(sic) than iOS after starting from behind.

Because your dev machine for this new language can't be more then 6 years old? Yeah, sure.

No, because your dev machine for this new language has to run a particular operating system, and most indy devs won't throw out a grand for a machine with no guaranteed payback.

Re:Prerequisites

[Anonymous Coward]

A key takeaway:No wonder Android has more Apps(sic) than iOS after starting from behind.

Yes, but is that sufficient reason to endure the pain of actually using Android?

Re:Prerequisites

[iluvcapra]

I'm uncertain of the statistics on this, but whenever I see photos of "Indy dev" conferences I always see a lot of silver laptops with glowing fruit. I think most of these people are already equipped.

Re:Prerequisites

[Half-pint HAL]

Well here's a question for you then... do most indy devs go to indy dev conferences? I've never been to one....

Re:Prerequisites

[MaryAnnEvans]

Android only has more apps if you count malware and crapware. The app store guidelines and the need to get past a human tester is far more of a restriction on app numbers than the need to have Mavericks. The number one reason for app rejections is the discovery of bugs by the approvals staff. Equivalently buggy apps will find their way into the Android stores without any barrier.

Re:Prerequisites

[MaryAnnEvans]

and most indy devs won't throw out a grand for a machine with no guaranteed payback.

Good. With 1.3 million apps in the Apple App Store, there's enough already. Cutting out people who by their choice of PC show themselves to be less aware of good design is no bad thing.

Re:Prerequisites

[MaryAnnEvans]

Those that do go to conferences show themselves to be open to new ideas and to networking with other developers. Are they likely to be better or worse developers on average than those that don't go?

Re:Prerequisites

[Half-pint HAL]

I don't buy that logic. Some people who go to conferences will be posers who are still playing at being devs, but will never release a product.

Re:Prerequisites

[Half-pint HAL]

and most indy devs won't throw out a grand for a machine with no guaranteed payback.

Good. With 1.3 million apps in the Apple App Store, there's enough already. Cutting out people who by their choice of PC show themselves to be less aware of good design is no bad thing.

That, mate, is what we call "bigotry". There are many factors influencing choice of development machine. For the dev with a family, that includes paying for the kids' clothes.

Re:Prerequisites

[MaryAnnEvans]

If your development income isn't paying for your development machine, then you're not a professional. I'd rather buy from professionals than amateurs.

Re:Prerequisites

[MaryAnnEvans]

Note the words "on average". For sure there will be some people such as you describe. But their proportion is a hell of a lot higher amongst those who's only commitment was downloading an SDK.

self linking content now?

[dnebin]

You typed "I love Dice".

we're self linking now?

A language that only runs on one platform

[Anonymous Coward]

Is pretty useless.

AAAAAAAADDDDDDD!

[Anonymous Coward]

Buy now! But wait! There's more!

Yeah but does it run on

[slashdice]

The 1.0 syntax was just barely frozen. There are a couple open source swift implementations (check github... you won't find them on source forge!) that are making progress. Not sure how useful it would be without a Cocoa/OpenStep library, though.

self linking content now?

[slashdice]

And hosted on source forge. Which makes it the first new source forge project in 6 months.

SWIFT will be great for agile development ...

[PPH]

... Tom said spryly.

YACC

[callahan2211]

Yet Another Programming Language

Re:FUCK cross-platform development!

[Anonymous Coward]

"Hey guys I'm too lazy to write code that's optimized for each platform! I know.. I'll make it crap on ALL platforms!"

You pussies need to start learning to write software for each and every platform. That's always better in the end.

No pain no gain, you pussy.

I guess a pussy knows what pain is

More Swift Shennanigans

[Anonymous Coward]

I've been learning Swift for the last few months. My last few years have been solid ActionScript 3 and I've really enjoyed the move. "Proper" strong typing, didSet observers, optionals, generics, and so on and so on are all a happy revelation to me.

I'm now tinkering with everything from component creation to Grand Central Dispatch for threading to drawing Hermite spline curves to applying filters to images to fluid dynamics. If you're on the London Underground and see a chap frantically typing on a little Mac Book, that'll be me.

I have a blog which is a diary of my progression in Swift, and might be a good resource for Swift newbies (especially those with an AS3 or Flex background). All my source code is open and available on GitHub: http://flexmonkey.blogspot.co.uk/search/label/swift

WARNING

[Anonymous Coward]

I started the tutorial but it has a subliminal effect. After a minute you will start having gay fantasies.

I perfer Blackberry's dev tools

[Anonymous Coward]

I know people can't DL it. Because no one seems to have a BB10 phone. But Crackberry has an app for it. They wrote the entire app in one weekend. And I have to say that it is quite impressive and simple to use. Using similar apps on Android give an inconsistent and crippled experience. Blackberry apps are quick to author and extremely easy to interact with. Mostly thanks to the Cascades framework for UIs they provide.

It;'s a shame that everyone is brainwashed into thinking Apple and Samsang are the only smartphone makers. If people started buying BB10 phones, more great apps would quickly appear. Granted the ones I care about exist already. And are in most cases better than anything on Android and iOS. Even the stock music player on BB10 (written with Cascades I believe) is 10x easier to use than anything I have ever experienced on Android.

Fizz

[Anonymous Coward]

Anyone else notice that Swift backwards sounds like Fizz?