Book Image

iOS 15 Programming for Beginners - Sixth Edition

By : Ahmad Sahar, Craig Clayton
5 (1)
Book Image

iOS 15 Programming for Beginners - Sixth Edition

5 (1)
By: Ahmad Sahar, Craig Clayton

Overview of this book

With almost 2 million apps on the App Store, iOS mobile apps continue to be incredibly popular. Anyone can reach millions of customers around the world by publishing their apps on the App Store. iOS 15 Programming for Beginners is a comprehensive introduction for those who are new to iOS. It covers the entire process of learning the Swift language, writing your own app, and publishing it on the App Store. Complete with hands-on tutorials, projects, and self-assessment questions, this easy-to-follow guide will help you get well-versed with the Swift language to build your apps and introduce exciting new technologies that you can incorporate into your apps. You'll learn how to publish iOS apps and work with Mac Catalyst, SharePlay, SwiftUI, Swift concurrency, and much more. By the end of this iOS development book, you'll have the knowledge and skills to write and publish interesting apps, and more importantly, to use the online resources available to enhance your app development journey.
Table of Contents (32 chapters)
1
Part 1: Swift
10
Part 2: Design
15
Part 3: Code
25
Part 4: Features

Understanding functions

Functions are useful for encapsulating a number of instructions that collectively perform a specific task, for example:

  • Calculating the 10% service charge for a meal at a restaurant.
  • Calculating the monthly payment for a car that you wish to purchase.

Here's what a function looks like:

func functionName(parameter1: ParameterType, ...) -> ReturnType {
   code
}

Every function has a descriptive name. You can define one or more values that the function takes as input, known as parameters. You can also define what the function will output when done, known as its return type. Both parameters and return types are optional.

You "call" a function's name to execute it. This is what a function call looks like:

functionName(parameter1: argument1, …)

You provide input values (known as arguments) that match the type of the function's parameters.

Important Information

To learn more...