Start - Software Engineering

Golang getting started

Are you an aspiring software developer in need of guidance? then this material is for you. First you'll learn the basics of programming. The goal is for you to understand some of the concepts used while programming. There are plenty of examples for you to learn from along the way. But let's start of by setting up your computer with the minimum required tools for programming.

Editor, compiler and terminal

EDITOR: The first thing you need is a text editor. There are plenty to choose from. Below are two editors I think are a good starting point. There are lots of others with varying complexity but don't start with those unless you're already familiar with them. The important thing is, it has to be a text editor, Not a word processor like Word.

COMPILER: You'll be using the Go programming language. It and the compiler are available from https://golang.org/dl. Follow the installation instructions carefully and make sure it works.

TERMINAL: Once a program is written you'll want to execute it. Without a graphical user interface you do this in a terminal. The terminal is a small program which enables you to type in commands. When you hit the enter key, the command is executed. The go compiler that you installed earlier is such a command. If you followed the installation instructions thoroughly, you should already have used the terminal so I assume you know where to find it.

Styling conventions

Throughout this material; commands are indicated with a gray background with a darker left border. Commands start after the $ character, and other lines are the output of the command.

$ go version
go version go1.14 linux/amd64

Note! when asked to enter a command do not enter the first $ character, only what is after it. Source code is presented in two ways; an entire file has a gray background with a solid border.

package main

func main() {}
whereas partial content is without borders.
func main() {}
Side note; emphasizing an important concept.

There is a lot to learn and whenever a section includes many concepts or longer explanations I'll add a side note with the Most important thing. Also the material is formated in such a way that if you choose to print it out there is room for your own notes on the left hand side.
Ok, you have the tools up and running and you understand how to read this material. It's time to learn programming.

Setup working directory

First; use the terminal and create a folder where you will be working.

$ cd $HOME
$ mkdir go-learn
$ cd go-learn

Your first program

package main

func main() {
	print("Hello, world!\n")
}

Create a file in your editor and then type in the above code. Save it as main.go and run the program in the terminal as shown below.

$ go run .
Hello, world!

Let's step through each line in the program. The first line tells the compiler that this file is part of a package called main. Go uses packages to group files in larger projects. The main package is special in that it also indicates this should be compiled into a executable command. The keyword func declares a function which we call main. Inside main package you have to have one main function which the compiler uses as a starting point when running your command.

In the above example the code is nicely formatted for easy reading but it doesn't have to be. These variations work just fine

package main; func main() { print("Hello, world!\n") }
package main
func main() {
print("Hello, world!\n")
}

You don't want to spend to much time adding spaces and tabs so your code looks good, let the computer do it for you. For this you will use the gofmt command.

$ gofmt -w main.go
Keep code perceptible!

Replace main.go with the name of whatever file you want to format. Keep your code nicely formattted, it improves readability for you and others. As you get more experienced you'll notice that most of your time is spend on reading code than writing it, so readability is a key point in being productive. Make it a habit to always keep code perceptible.