iOS App Development from Scratch: What You Need to Know

If you’re an aspiring mobile app developer looking to learn how to build an iOS app, this post is for you! The world of mobile app development can be daunting, especially when you don’t know where to start. I have put together a guide of what you need to learn in order to get the ball rolling on your first iOS app. Let’s dive in!

iOS Programming Basics

What Programming Language do you need to learn?

To begin building an iOS app, you first need to become familiar with programming languages like Swift and Objective-C. These are the two most popular languages used to develop apps for Apple devices. Most new apps today are written in Swift.

Swift is quickly becoming the preferred language for iOS app development, as it offers developers greater flexibility and faster coding than Objective-C. Swift has a more intuitive syntax, making it easier to learn and write code with fewer mistakes. It also allows developers to use modern programming concepts like generics and closures, which can make apps more efficient and reliable. Additionally, Swift provides better memory management support than Objective-C, resulting in improved app performance. All these features make Swift the ideal choice when developing an iOS app from scratch.

How much about Swift do I need to know?

If you’re a beginner, you don’t need to be an expert in Swift. But knowing the basics is essential. It’s important to understand variables, constants, data types, conditionals (if-else statements), loops (for and while loops) functions/methods, classes/objects, and memory management. These concepts should be enough to get you up and running with your first app.

 

If coding isn’t your strong suit, there are plenty of online resources. Here are some of my recommendations:

Books:

• Develop in Swift Fundamentals

Youtube tutorials:

• Swift Basics Tutorial series
• Learn the Essentials of Swift in one hour
• Swift Programming Tutorial for Beginners

Apple Developer Tools

Once you have a handle on programming fundamentals, it’s time to download Xcode—Apple’s official development suite for creating iOS apps—from the Mac App Store. Xcode contains all the tools needed for developing iOS apps such as storyboards and Xcode previews (for designing user interfaces) and simulators (for testing apps).

Xcode has a lot of features and can feel overwhelming in the beginning. Spend some time familiarising yourself with the Xcode interface.

Youtube tutorials:

• Xcode 14 Tutorial – Beginner Introduction to iOS App Development with SwiftUI in 2023
• Xcode 14 Tutorial – Step by Step for Beginners (2022)

Blog posts:

• Learn how to build apps

Building the User Interface

You have the options to use UIKit or SwiftUI. UIKit is the traditional approach to building user interfaces for iOS apps and has been around since the early days of iOS development. SwiftUI is a newer, more modern approach to creating user interfaces that are gaining popularity.

SwiftUI uses a declarative syntax to create user interfaces quickly with less code and can be used in conjunction with UIKit, giving developers a powerful combination of tools.

No matter which one you choose, there are plenty of resources to help you get up and running.

What should I use, if I want to make my own app?

SwiftUI is the preferred choice for developing an iOS app from scratch. Along with being easier to learn and write code, it uses less code than UIKit, making it more efficient and reliable.

What should I learn if I want to have a career as an iOS developer?

If you want to pursue a career as an iOS developer, it’s important to have a strong understanding of the basics. This includes learning the fundamentals of Swift and Xcode, as well as understanding UIKit or SwiftUI (whichever you decide to use). Most likely we will use both frameworks in the future. Check your local job board to see what is the preferred requirement.

How to learn SwiftUI

To learn SwiftUI, it is important to have a structured approach that covers the fundamental concepts, including

• creating and modifying views,
• working with images and text views
• layouts
• using control views like buttons and toggles
• working with ForEach, List, and ScrollView
• navigation with NavigationView, NavigationStack, and TabView
•  presenting views with sheets and alerts,

as well as more advanced topics like

• state-driven and declarative programming
• data flow and property wrappers
• architecture patterns like MVVM
• state restoration
• animating views
• using gestures

To become proficient in SwiftUI, practice is key. Developers should work on building their own projects and experimenting with the different features of the framework. They should also stay up to date with new releases and updates, as SwiftUI is a constantly evolving framework. 

While it may take time and effort to become comfortable with SwiftUI, the rewards of building beautiful and functional apps are well worth it.

Resources:

• iOS App Dev Tutorials from Apple
• SwiftUI course
• learn how to use SwiftUI and Core Data to build a complex app

How to learn UIKit

To learn UIKit, developers should start by learning the basics of the framework, including

• what are UIView and UIViewController
• view controller lifecycle
• table views and delegates
• UICollectionView and datasource
• storyboards
• explore different types of UI components, such as buttons, text fields, and pickers
• learn how to use Auto Layout to create responsive and adaptive layouts
• use animations to add dynamic visual effects to their applications

as well as more advanced topics like

• Model-View-Controller pattern
• UIApplicationDelegate
• navigation with UINavigationController and UISplitViewController

 

Practice is key to becoming a proficient iOS developer. Take the time to work.

Resources:

• iOS App Dev Tutorials from Apple

Working with Data

It is important to work with the user’s data. For example, you need to be able to save the data locally on an iPhone. You also need to be able to store the data securely in the cloud and access it from multiple locations. Here are some technologies that you will use more frequently:

• in the file system with FileManager
• UserDefaults
• Core Data for complex data.

Some additional more advanced options to store data offline are:

• iCloud sync with Core Data
• Realm database
• Firebase and Firestore
• AWS

Resources:

• How to store data in an iOS app? – Introduction to data persistence in Swift locally and with sync

Working With the Web

Additionally, you should be able to work with JSON and URLSession.

• iOS Swift Tutorial: Working with the Web: HTTP, URL, and REST API
• iOS Swift Tutorial – Working with the Web – How to parse JSON into model objects with Codable
  
• SwiftUI Tutorial: How to make an API call, fetch JSON, and structure your networking layer with MVVM
  
• Loading and caching images from URL in SwiftUI – AsyncImage or custom view model logic
• Book recommendation: Develop in Swift Data Collections, Chapter 2.4

Design Patterns

When developing with UIKit, you should learn about the Model-View-Controller (MVC) design pattern. This is a popular way of organizing code that separates the data from the user interface. It can help keep your code clean and organized. For SwiftUI, it is more popular to use Model-View-View-Model (MVVM).

You should also be familiar with other design patterns such as Dependency Injection, Delegation, and Observer. These will help you write better code by organizing it in a logical way that is easy to maintain.

Blog posts:

• MVVM with SwiftUI

Examples for more complex apps in SwiftUI

• iTunes Search App – Build a complex SwiftUI app

Testing

When developing apps, you should take the time to test your code thoroughly. Unit testing is a great way to ensure the features of your app work as expected. You should also be familiar with UI and integration testing, which can be done with XCTest.

Finally, you should also have the ability to debug your code and find any issues that may arise. Debugging can help you identify problems quickly and make sure that your code is running as expected.

Source Control

Source control is an important tool to help you keep track of changes in your code. It allows you to go back and look at previous versions of the code and make sure that any changes you are making don’t break anything. Take some time to learn Git with Xcode. You will likely be required to share your code on GitHub. This is a great skill if you plan to start a career as an iOS developer.

Design Guidelines

The next step is learning how Apple recommends developers design their apps. You can learn more about the human interface guidelines on Apple’s developer platform. Additionally, it helps to understand some basic principles of graphic design like color theory and typography so that your app looks great on any device.

How to publish an app to the App Store

Once you have completed your app, it is time to publish it to the App Store. This involves setting up an Apple developer account and creating a certificate and provisioning profile. Once you have these set up, you can use Xcode to submit your app for review. The App Store requires that apps have to follow their guidelines, so make sure you read them carefully before submitting. Finally, once your app has been approved, you can publish it to the App Store.

Conclusion

Creating an app for Apple devices requires a lot of knowledge and skill. You need to develop an understanding of the technologies involved, such as Swift, UIKit, and/or SwiftUI. You should also be familiar with design patterns, testing, debugging, source control, and the App Store publishing process. With practice and dedication, you can learn how to create amazing apps for Apple devices.