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

The Go source file


We have seen, in Chapter 1, A First Step in Go, some examples of Go programs. In this section, we will examine the Go source file. Let us consider the following source code file (which prints "Hello World" greetings in different languages):

golang.fyi/ch02/helloworld2.go

A typical Go source file, such as the one listed earlier, can be divided into three main sections, illustrated as follows:

  • The Package Clause:

          //1 Package Clause 
          package main 
    
  • The Import Declaration:

          //2 Import Declaration 
          import "fmt" 
          import "math/rand" 
          import "time" 
    
  • The Source Body:

          //3 Source Body 
          var greetings = [][]string{ 
            {"Hello, World!","English"}, 
            ... 
          } 
     
          func greeting() [] string { 
            ... 
          } 
     
          func main() { 
            ... 
          } 
    

The package clause indicates the name of the package this source file belongs...