Book Image

Mastering Swift 5.3 - Sixth Edition

By : Jon Hoffman
Book Image

Mastering Swift 5.3 - Sixth Edition

By: Jon Hoffman

Overview of this book

Over the years, Mastering Swift has proven itself among developers as a popular choice for an in-depth and practical guide to the Swift programming language. This sixth edition comes with the latest features, an overall revision to align with Swift 5.3, and two new chapters on building swift from source and advanced operators. From the basics of the language to popular features such as concurrency, generics, and memory management, this in-depth guide will help you develop your expertise and mastery of the language. As you progress, you will gain practical insights into some of the most sophisticated elements in Swift development, including protocol extensions, error handling, and closures. The book will also show you how to use and apply them in your own projects. In later chapters, you will understand how to use the power of protocol-oriented programming to write flexible and easier-to-manage code in Swift. Finally, you will learn how to add the copy-on-write feature to your custom value types, along with understanding how to avoid memory management issues caused by strong reference cycles. By the end of this Swift book, you will have mastered the Swift 5.3 language and developed the skills you need to effectively use its features to build robust applications.
Table of Contents (23 chapters)
21
Other Books You May Enjoy
22
Index

Using case and where statements with conditional statements and loops

As we saw with switch statements, the case and where statements within a switch statement can be very powerful. Using case and where statements within our conditional statements can also make our code much smaller and easier to read. Conditional statements and loops, such as if, for, and while, can also make use of the where and case keywords. Let's take a look at some examples, starting off with using the where statement to filter the results in a for-in loop.

Filtering with the where statement

In this example, we take an array of integers and print out only multiples of 3. However, before we look at how to filter the results with the where statement, let's take a look at how to do this without the where statement:

for number in 1...30 { 
    if number % 3 == 0 {
        print(number)
    }
}

In this example, we use a for-in loop to cycle through the numbers 1 to 30. Within the for-in...