Lesson 1
Getting Started with Go

Go is an open source programming language developed and distributed by Google. In this lesson, we will walk through the steps of installing Go on a computer running Microsoft Windows 10 or later.

LEARNING OBJECTIVES

By the end of this lesson, you will be able to:

• Download and install Go on a local computer.
• Test the installation to verify it works.
• Create and run a Hello, World! program.
• Demonstrate basic troubleshooting steps.
• Use an online editor with Go.
• Ensure consistent formatting of your Go programs.

NOTE There are also versions of Go for Apple macOS and Linux that you can download. The process should be somewhat similar to what is shown in this lesson.

INSTALLING GO

There are several requirements for installing Go. First, you must have administrative rights on your computer. If you own the computer, you should have no problems. If you are using a work or school computer, contact your IT department if you run into permission problems during the installation process.

NOTE If you have used Go in the past and already have it installed on your computer, you can skip the installation instructions and go straight to the testing steps.

Alternatively, if you have an older version of Go that you would like to update, you might want to remove the existing version before installing the updated version.

You will also need a text or code editor to create Go programs. Go programs are written in plain text, so if you already have an editor you like, you can continue using it. If you have never used a code editor before or if you want to try a different one, you can use one of the following:

• Visual Studio Code
• (downloadable from https://code.visualstudio.com)
• Atom
• (downloadable from https://atom.io)

You can also find additional editors that support Go by going to the "Editor plugins and IDEs" page on the Go site. The page is found at https://go.dev/doc/editors.html. You can also use a plain-text editor such as Notepad if you prefer; however, an editor that supports Go, such as Visual Studio Code or Atom, will provide tools to help you with errors in your code.

Downloading the Installation Files

The first step is to download the most current version of the installation files. You can find the files on Go's Downloads page at https://go.dev/dl. The instructions shown in Figure 1.1 are for version 1.17.2 for Windows, but you will likely see a more recent version on the page.

Click the link for your operating system in the Featured Downloads section of the page. This will download the necessary installation file or package for your operating system.

Figure 1.1: The Go Downloads page

Starting the Installation of Go

Once you have downloaded the installation file, open it from your computer. In Windows, you can open it by simply clicking the filename. This will start the Setup Wizard, as shown in Figure 1.2.

Click Next to begin the installation. The next screen displays the End-User License Agreement, as shown in Figure 1.3.

Go is distributed under an open source license. This means that you can modify and/or redistribute the code if you wish, but you must include the same copyright notice in any package you distribute.

You should read through the licensing agreement and then select the check box to accept it. Click Next to continue the installation. The next screen, shown in Figure 1.4, asks you to specify the destination folder where Go will be installed.

Figure 1.2: The Go Setup Wizard

Figure 1.3: The Go End-User License Agreement

Figure 1.4: Specifying the folder where Go will be installed

You can either accept the default location or set a new location by entering the path to a folder or by clicking on Change to select a new location to install Go. Once you've entered the destination folder, click Next again. On the next screen, click the Install button to start the installation. Note that you might be prompted by Windows asking if you give permission to install the application. If so, you will need to indicate that it is okay.

When the installation is complete, you will see a confirmation message when the installation is complete, similar to what is shown in Figure 1.5. You can click the Finish button to close the wizard.

Figure 1.5: Confirmation that Go is installed

NOTE If you are using the MSI installer shown here, it will also set up your computer with the required environment variables during the installation.

TESTING THE INSTALLATION

After completing the installation, you should test to make sure Go works. To do this in Windows, start by opening a command-line window. Click the Start Menu and type cmd in the search box. You can then open the command prompt from the search results, as shown in Figure 1.6.

NOTE Alternatively, you can open the command prompt by pressing Windows key+R, entering cmd, and clicking the OK button.

Figure 1.6: Running the command prompt (Microsoft Windows 11)

The command prompt will open in a new window similar to Figure 1.7. You should see a prompt that ends in your username.

Figure 1.7: The command prompt

At the prompt, type the following command and press Enter:

This command checks that Go is installed on your computer and displays the version number if it is. You should see a version that matches the one you just installed. Figure 1.8 shows version go1.17.2 installed.

If you get an error message instead of a version number, repeat the installation instructions and try again.

The default installation shown here used the MSI file. If entering the code snippet displayed the version number, then you should be ready to continue creating your first program, Hello World!.

If you downloaded a zip file instead of an MSI file, you will need to manually set up Windows environment variables before using Go. You can either delete the files created from the zip file and reinstall using the MSI file (which sets up the variables during the installation) or use the instructions provided in Go's Download and install page at https://go.dev/doc/install.

Figure 1.8: Displaying your Go version

CREATING A HELLO, WORLD! PROGRAM

With Go installed on your machine, you are ready to write and run your first Go program, Hello, World!. Using your preferred text or code editor (such as Atom or Visual Studio Code), create a file named gotest.go and save it to a known location, such as your Documents folder. In the example presented in Listing 1.1, the file is saved in Documents\GoLang. If you choose a different location, you will need to modify the instructions for compiling and running the program.

Make sure that the file has the filename extension .go. Most text or code editors will allow you to specify your own extension. Verify that the Save As box is set to All Files (or something similar) rather than a specific extension, such as .txt.

Add the code shown in Listing 1.1 to your new file.

LISTING 1.1
Hello, world!

At this time, you are not expected to understand all the code presented in Listing 1.1; however, it is worth taking a closer look. You start by creating a main package to serve as the starting point for your program. You follow this by using the import statement to import Go's formatting package fmt. The fmt package contains code that allows text to be printed to the screen.

NOTE The nice thing about using a package like fmt is that you can use it without having to worry about the code. In Listing 1.1, you can use fmt.Println without having to know what code is being used to actually do the printing.

You create a main() function in the third line of code, and you print the phrase "Hello, world!" by using Println from the fmt package you included. You don't need to understand how this works right now-just know that fmt.Println("") will print whatever is between the double quotes to the screen.

After entering the listing, make sure you save the file. You should leave the file open in your text editor in case you have problems running it. The compiler will read only the saved content in the file.

Compiling and Running the Program

The next step is to compile the file. Compiling is the process of converting human-readable code into machine-readable code. Use the cd command to...