Book Image

The Go Workshop

By : Delio D'Anna, Andrew Hayes, Sam Hennessy, Jeremy Leasor, Gobin Sougrakpam, Dániel Szabó
Book Image

The Go Workshop

By: Delio D'Anna, Andrew Hayes, Sam Hennessy, Jeremy Leasor, Gobin Sougrakpam, Dániel Szabó

Overview of this book

The Go Workshop will take the pain out of learning the Go programming language (also known as Golang). It is designed to teach you to be productive in building real-world software. Presented in an engaging, hands-on way, this book focuses on the features of Go that are used by professionals in their everyday work. Each concept is broken down, clearly explained, and followed up with activities to test your knowledge and build your practical skills. Your first steps will involve mastering Go syntax, working with variables and operators, and using core and complex types to hold data. Moving ahead, you will build your understanding of programming logic and implement Go algorithms to construct useful functions. As you progress, you'll discover how to handle errors, debug code to troubleshoot your applications, and implement polymorphism using interfaces. The later chapters will then teach you how to manage files, connect to a database, work with HTTP servers and REST APIs, and make use of concurrent programming. Throughout this Workshop, you'll work on a series of mini projects, including a shopping cart, a loan calculator, a working hours tracker, a web page counter, a code checker, and a user authentication system. By the end of this book, you'll have the knowledge and confidence to tackle your own ambitious projects with Go.
Table of Contents (21 chapters)
Free Chapter
1. Variables and Operators
2. Logic and Loops

The init() Function

As we have discussed, every Go program (executable) starts in the main package and the entry point is the main function. There is another special function that we should be aware of, called init(). Each source file can have an init() function, but for now, we will look at the init function in the context of the main package. When you start writing packages, you might need to provide some initialization (the init() function) for the package. The init() function is used to set up states or values. The init() function adds initialization logic for your package. Here are some examples of uses of the init() function:

  • Setting database objects and connections
  • The initialization of package variables
  • Creating files
  • Loading configuration data
  • Verifying or repairing the program state

The init() function requires the following pattern to be called:

  • Imported packages are initialized first.
  • Package-level variables are initialized.
  • ...