New Features of Swift 5 to Consider During iOS App Development

iOS App Development

Swift is one of the most popular programming languages widely used to create scalable, feature packed and high performing iOS applications. The new Swift 5 update is the talk of the town these days. So, in this blog we are going to explain some most popular feature of this programming language with some screenshots. This language has replaced the Objective-C as the main programming language for the Apple-related software.

Why Is Swift Better for iOS App Development?

Swift is a new and modern language. In the beginning, there was a bit of hesitation from a lot of developers wondering whether or not they should adapt this new technology because it was new and didn’t really know whether or not Apple is going to fully support it later. A few reasons why developers use this language because it's easy to use. Secondly, the Swift documentation is written and presented in the Xcode IDE and for the most part it's documented pretty well and very similar to the way objective-c is presented. And, the last but not least Swift programmed mobile apps are considered to fast performing and easy to load.
Let’s have a quick look at some important changes in Swift 5 that you need to know about: 

ABI Stability

In this pointer, we're going to talk about is an ABI stability that’s finally coming into Swift 5. It is the application binary interface, which is a binary equivalent of an API. Mobile app development companies use various API of libraries to write code using Swift for their apps. The UIKit framework-- for example-- gives API to interface with labels, buttons, and various view controllers. 

When any user downloads and installs the mobile app with ABI stability, they will not have to download the entire source code of your mobile app. Most of these codes are already present on the iPhone, as part of iOS libraries and frameworks. With the help of ABI stability, mobile apps will be smaller, faster, and more accessible.

Working With Strings & Enums

Here, we're going to be looking at some of the new features of series five that's improved working with strings and enums. The first feature that we're going to be looking at is adding a raw string. Before Swift 5, we had to use the escape characters when dealing with single and double quotes within a string. This can be very tedious and can also take time, especially in a very long string. In Swift 5, we cannot use raw strings, which means we don't have to escape some of these special characters within a string. 

I'm going to create a straightforward string and within this string, we're going to have of some double quote: 

So this is a person asking any question that is normally supposed to be in a quote. He said, “see you next week,” and I replied, “good night” we're trying to create a string that has a quote within a quote. Swift is not able to process all of this quotation, so this means that we need to escape the quotes that we want to show as part of the string. You need to do is make sure you put a backslash before the code so if we put the backslash,

If you look at the debug area, you can see that these strings are actually printing all of the codes, which is exactly what we want in such a situation. We have to work with very long strings can be very tedious if you have to escape all of this quotation manually. So you have to look within the string and then find each one of the double-quotes. And then manually escape it black can be very tedious. So this is why Swift has introduced something called a Ross.  

Module stability

Now let us talk about module stability with module stability in place. Modules are written in Swift 5.1 will still work in future Swift versions without breaking. Suppose you developed a framework now in Swift 5.1 and you have not modified it in a year because it has no bugs or no features were added. In that case, you will not be required to update or recompile your framework even if the developers using it are writing their app or library with a newer Swift version or compiler. With this, more and more developers now will use Swift because of these two new features and won't have to worry about migrating older code to newer code in the future.

Dictionary Literal Renamed 

The dictionaryLiteral class has now been renamed to key-value pairs. We are going to be looking at the reason why the name change was made. The best way to demonstrate why the name change was made is to create an example of using a DictionaryLiteral and then comparing it to how we use the normal dictionary. 

So we can't be creating a dictionary and then a dictionary literal, and that's going to give us an understanding of why the name change was necessary. Here we have created a simple dictionary:

One of the main reasons the name change was made was that the DictionaryLiteral has nothing to do with a dictionary even though they look the same. The way they actually work is different and you can see that there are significant differences between them. This is why the Swift community thought it is better to even change the name and call them key-value pairs, which I believe is also the right name. So now don't call them the DictionaryLiteral so we can remove this, and we can just describe it as a key-value pair.

Swift Package Manager & Other Changes

Here we're going to be looking at what's new in Swift package manager and also discuss other minor updates to Swift 5. The first package manager featured are going to be looking at is called a dependence in mirroring which is a new feature in Swift 5 where you be able to have access to a dependency, even if the original source of the dependency is no longer available so that you can continue to be with your project. There are 3 reasons why you may want to mirror a dependency:

•    The first of these reasons is availability so that's when the original source is unavailable or when it is deleted you can ensure that your dependency will always work because you have a mirror.
•    The second reason is cache. If the original source is very slow to fetch, you may want to cache it locally so you may want to use a mirror for this purpose.
•    Finally, you may want to mirror a dependency to test it before you make it available in your project for all your users.

Another feature that Swift 5 added to package manager is the platform deployment settings. In addition to this, Swift 5 allows you to specify the minimum required platform deployment target version in the package.swift manifest file. You can switch the minimum required version of the platform for your package. 

For example, you may want to the package to be used in iOS version 12 or above. So if you've also added support for commonly used target specifically settings so that if you have multiple targets in your project, you can have different view settings for these targets. This gives you a lot of flexibility in our different targets can have different build settings and different behavior for the package. 

These are the 3 major changes in package manager in Swift 5. We have the dependency mirroring, we have the platform deployment settings and finally we have the target specific settings. 

Swift 5 Migration Assitance 

Here we will look at is how to use the swift migration assistance to convert an old Swift project to the current swift syntax. What we're going to be looking at how to migrate an old project to swift 5 and also understand ABI stability.


This is Xcode 10.2 and inside the “viewDidLoad”, you can see that we have a statement with a deprecated variable. You can also see that we currently have two issues. If you click on that issue, you can see that we have the same one in here which says the encoded offset is deprecated but we also have the conversion to swift 5 available message. If you launch an old project for the first time, you're going to get the Swift migration assistant which is going to try and help you to convert some of the old Swift syntax to the latest code. But, if you don't see the migration assistant you can also click on conversion to a swift 5 available message. And than you can see that that's also launched the migration assistant.

There is another way to launch the migration assistant which can be seen by clicking convert later and then going to the Edit menu. There you can see convert and is going to try to convert it to the current Swift syntax. You can also see that that's also launched the migration assistant next and it's going to go through all your codes. It's going to show you code that it is going to convert on the left hand side. 

Here you can see that it is selecting the view controller the swift and this is the only code file that we have in our projects currently that has breaking changes. So what you can see here is that Swift is going to convert this statement array index of 9 so we want to get index of 9 which is what is supported in version 4.2. Swift 5 introduced the first index of and I think this makes more sense because we have three nines inside of our array and going to return the index of the first value that matches what we're looking for.

It's going to show you all of the changes that is going to be made to your file. You can scroll through the file to see what is going to be changed. If you are happy with a suggestion all you need to do is click on this save. You're going to get a warning so that you can commit to your changes before you make any of this change. 

You can simply going to click on continue and you can see that the code has been modified successfully. So index of 9 has been changed to the first index of 9 which means your code is now swift 5 compatible. So if we go back to the issue navigator, you do not have the one anymore that is asking us to convert it to 5. This is the most important part of migrating an old project to Swift 5. The migration assistant is going to help you to convert all of the old Swift source code to the latest Swift syntax. 

Let’s Wrap Up:

I hope in this blog, all your donuts related to Swift 5 latest features have been resolved. If you ar a business owner and want to have your own Swift based iOS mobile app, you should contact a reputed ios app development company having a track record of successful mobile apps on this platform.

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