Book Image

The Go Workshop

By : Delio D'Anna, Andrew Hayes, Sam Hennessy, Jeremy Leasor, Gobin Sougrakpam, Dániel Szabó
5 (2)
Book Image

The Go Workshop

5 (2)
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
1. Variables and Operators
2
2. Logic and Loops

defer

The defer statement defers the execution of a function until the surrounding function returns. Let's try to explain this a bit better. Inside a function, you have a defer in front of a function that you are calling. That function will execute essentially right before the function you are currently inside completes. Still confused? Perhaps an example will make this concept a little clearer:

package main
import "fmt"
func main() {
  defer done()
  fmt.Println("Main:  Start")
  fmt.Println("Main:  End")
}
func done() {
  fmt.Println("Now I am done")
}

The output for the defer example is as follows:

Main: Start
Main: End
Now I am done

Inside the main() function, we have a deferred function, defer done(). Notice that the done() function has no new or special syntax. It just has a simple print to stdout.

Next, we have two print statements. The results are interesting. The two print statements...