Book Image

Learning Go Programming

Book Image

Learning Go Programming

Overview of this book

The Go programming language has firmly established itself as a favorite for building complex and scalable system applications. Go offers a direct and practical approach to programming that let programmers write correct and predictable code using concurrency idioms and a full-featured standard library. This is a step-by-step, practical guide full of real world examples to help you get started with Go in no time at all. We start off by understanding the fundamentals of Go, followed by a detailed description of the Go data types, program structures and Maps. After this, you learn how to use Go concurrency idioms to avoid pitfalls and create programs that are exact in expected behavior. Next, you will be familiarized with the tools and libraries that are available in Go for writing and exercising tests, benchmarking, and code coverage. Finally, you will be able to utilize some of the most important features of GO such as, Network Programming and OS integration to build efficient applications. All the concepts are explained in a crisp and concise manner and by the end of this book; you would be able to create highly efficient programs that you can deploy over cloud.
Table of Contents (18 chapters)
Learning Go Programming
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Deferring function calls


Go supports the notion of deferring a function call. Placing the keyword defer before a function call has the interesting effect of pushing the function unto an internal stack, delaying its execution right before the enclosing function returns. To better explain this, let us start with the following simple program that illustrates the use of defer:

package main 
import "fmt" 
 
func do(steps ...string) { 
   defer fmt.Println("All done!") 
   for _, s := range steps { 
         defer fmt.Println(s) 
   } 
 
   fmt.Println("Starting") 
} 
 
func main() { 
   do( 
         "Find key", 
         "Aplly break", 
         "Put key in ignition", 
         "Start car", 
   ) 
} 

golang.fyi/ch05/defer1.go

The previous example defines the do function that takes variadic parameter steps. The function defers the statement with defer fmt.Println("All done!"). Next, the function...