Chapter 1

Hello, Go!

IN THIS CHAPTER

Understanding why Go is the wave of the future

Installing Go on your computer

Working with an integrated development environment

Writing a Go program and understanding how it works

Seeing how Go compares to other languages

Go is an open-source programming language - one of the fastest-growing programming languages around - released by Google in 2009. It's a multipurpose programming language specifically designed to build fast, scalable applications.

Go comes from a pretty impressive team of people: Ken Thompson (designer and creator of Unix and C), Rob Pike (cocreator of UTF-8 and Unix format), and Robert Griesemer (a Google engineer). If you're technically inclined, you may want to check out an article called "Go at Google: Language Design in the Service of Software Engineering" (https://talks.golang.org/2012/splash.article), which discusses how Go was initially conceived to solve problems at Google.

In this chapter, I explain why learning Go is important for your career, where Go can be used, and how to get started with Go programming.

Go is often referred to as Golang because of its web address: https://golang.org. However, the official name of the language is Go, so that's how I refer to it throughout this book.

Seeing What Learning Go Can Do for You

You can learn many programming languages today, but Go stands out from the others for a few reasons:

• Go is easy to learn. Go's syntax makes it a readable language. It has no support for object-oriented programming (OOP), which means you don't have to worry about classes and inheritance and the complexities that come with that.

  Object-oriented programming (OOP) is a programming paradigm that is based on the concept of objects (data). Instead of focusing on the functions and logics, OOP organizes software around data, or objects. A key concept in OOP is classes (sort of like templates). Suppose you want to display buttons in your application. Instead of writing the code to display each button individually, you can create a class to represent a generic button and use it to create buttons to display in your application. Each button has its own properties (characteristics). Using the concept of inheritance in OOP, you can create multiple subclasses of the button class to create different types of buttons, such as a rounded button, a rectangular button, and so on.

• Go has fewer features than other programming languages. You don't have to worry about the best way to solve a problem - there is only one right way to solve a problem in Go. This makes your codebase easy to maintain.
• Go excels in concurrent programming. Go's support for Goroutines makes it extremely easy to run multiple functions concurrently.

Go has no support for generics (the ability to specify the actual data type until it's actually used), but this may change as the language evolves.

If you still aren't convinced that you should learn Go, perhaps this next bit of news will motivate you: In the Stack Overflow Developer Survey 2019 (https://insights.stackoverflow.com/survey/2019), Go developers were the third highest paid in the industry, behind Clojure and F# developers.

Although Go has been around for quite a while (since 2009), only recently did it get wide adoption by developers, thanks to the proliferation of cloud computing and microservices. Today, Go has been widely used by major companies such as Dailymotion, Dropbox, Google, and Uber.

Here are some examples of where Go can be used:

• Cloud services: You can build scalable apps using Go on the Google Cloud Platform (GCP).
• Networking apps: With Go's support for Goroutines, you can use Go to build distributed servers and application programming interfaces (APIs).
• Web services: You can use Go to build scalable and efficient web services.
• Command-line apps: Because Go runs on multiple platforms, you can compile the same codebase and target different platforms (such as those running on macOS and Windows).

Installing Go on Your Machine

You're probably very eager to get started with Go programming on your machine, so let's get to it!

The easiest way to install Go is to go to https://golang.org/doc/install. This website automatically detects the operating system (OS) you're using and shows you the button to click to download the Go installer (see Figure 1-1).

FIGURE 1-1: Downloading the Go installer.

This book code has been written and tested using Go version 1.15. When you're reading this book, a new version of Go may have been released. In order to ensure that you can follow the examples in this book, I strongly suggest that you install the same version of Go that I've used. You can find it here:

• macOS: https://golang.org/dl/go1.15.8.darwin-amd64.pkg
• Windows: https://golang.org/dl/go1.15.8.windows-amd64.msi

If you want to be able to choose the Go installer for each of the supported operating systems (Linux, macOS, and Windows), and even see the source code for Go, go to https://golang.org/dl/.

After you've downloaded the Go installer, double-click the installer to start the straightforward installation process. I recommend that you just use the default installation settings - you don't need to change any of those settings.

In the following sections, I show you how to verify that your installation is performed successfully on macOS and Windows.

macOS

On macOS, the Go installer installs the Go distribution in the /usr/local/go directory. It also adds the /usr/local/go/bin directory to your PATH environment variable. You can verify this by entering the following command in the Terminal app (which you can find in the Applications/Utilities folder):

$ echo $PATH

You should see something like the following output (note the added path, highlighted in bold):

/Users/weimenglee/opt/anaconda3/bin:/Volumes/SSD/opt/anaco
nda3/condabin:/Users/weimenglee/flutter/bin:/Users/weimeng
lee/go/bin:/Users/weimenglee/.nvm/versions/node/v9.2.0/bin
:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/g
o/bin:/usr/local/share/dotnet:~/.dotnet/tools:/Library/App
le/usr/bin:/Library/Frameworks/Mono.framework/Versions/Cur
rent/Commands

Make sure to restart the Terminal app after you've installed Go in order for the changes to take effect.

To verify that the installation is correct, type the following command in Terminal:

$ go version

You should see the version of Go installed on your system:

go version go1.15.8 darwin/amd64

Windows

On Windows, the Go installer installs the Go distribution in the C:\Go directory. It also adds the C:\Go\bin directory to your PATH environment variable. You can verify this by entering the following command in Command Prompt (which you can find by typing cmd in the Windows search box):

C:\Users\Wei-Meng Lee>path

You should see something like the following output (note the added path, highlighted in bold):

PATH=C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\
Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WIND
OWS\System32\OpenSSH\;C:\Program Files\dotnet\;C:\Program
Files\Microsoft SQL Server\130\Tools\Binn\;C:\Go\bin;
C:\Program Files\Git\cmd;C:\Program Files\Graphviz
2.44.1\bin;C:\Program Files\CMake\bin;C:\Program
Files\Docker\Docker\resources\bin;C:\ProgramData\DockerDes
ktop\version-bin;C:\Program Files\MySQL\MySQL Shell
8.0\bin\;C:\Users\Wei-Meng Lee\AppData\Local\
Microsoft\WindowsApps;;C:\Users\Wei-Meng Lee\
AppData\Local\Programs\Microsoft VS Code\bin;C:\Users\Wei-
Meng Lee\.dotnet\tools;C:\Users\Wei-Meng Lee\go\bin

Make sure to restart the Command Prompt window after you've installed Go in order for the changes to take effect.

To verify that the installation is correct, type the following command in Command Prompt:

C:\Users\Wei-Meng Lee>go version

You should now see the version of Go installed on your computer:

go version go1.15.8 windows/amd64

Using an Integrated Development Environment with Go

To develop applications using Go, you just need a text editor (such as Visual Studio Code, TextEdit on macOS, or even the old trusty NotePad), and you're good to go (pun unintended). However, many developers prefer to use...