softchris / golang-book

A book on Go, contains fundamentals but also recipes

Go from the beginning

Welcome to Go from the beginning, a free book containing 25+ lessons that will take you from "zero to hero" in the amazing language Go.

Read online

https://softchris.github.io/golang-book/

Read offline/PDF/EPUB

https://leanpub.com/go-from-the-beginning FREE on LeanPub

Donate

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• Back and Alive (they are buying what the army requests and do public reports) https://comebackalive.in.ua
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• UNICEF, https://www.unicef.org/emergencies/war-ukraine-pose-immediate-threat-children

Table of content

Chapter	Title	Section	What you will learn	Lesson
01	Hello world	Basics	Why use Go and how to write your first program	Lesson
02	Using variables	Basics	How to declare variables with different data types and how to initialize and assign values	Lesson
03	Boolean logic with If and Else	Basics	How to work with boolean variables and create different execution paths with If, Else and Else If	Lesson
04	Converting between strings and numbers	Basics	How to use the strconv library to convert between primitives and strings.	Lesson
05	Loop statements	Basics	How to repeat statements and iterating over list structures and ways to control the loops	Lesson
06	User input	Basics	How to read user input from the console	Lesson
07	Functions	Basics	Reuse your code by creating functions. Learn how to deal with parameters and how to deal with returns and return types	Lesson
08	Error handling	Basics	How manage errors in your code. This will teach both how to produce errors as well as deal with them	Lesson
09	Arrays	Composite data types	Here we will learn about arrays, how to construct them, access items and iterate over them	Lesson
10	Structs	Composite data types	Structs enables us to collect many fields in one grouping, learn how to create and modify structs	Lesson
11	Maps	Composite data types	Maps make it easy to lookup items if you know the key. Maps have the notion of keys and values.	Lesson
12	Interfaces	Composite data types	Learn how you can model your data as interfaces and how to implement them	Lesson
13	Create your first project	Projects	Learn how to create your first project	Lesson
14	Consume external packages	Projects	Learn how to use external packages	Lesson
15	Create shared module	Projects	Create a module you can share with others	Lesson
16	Testing	Testing	Learn to test your code	Lesson
17	JSON	Web Dev	Learn to work with the JSON format	Lesson
18	Build a Web App	Web Dev	Learn how to build a web app capable of serving many different formats	Lesson
19	Logs	Miscellaneous	Use logging for better management of all kinds of messages in your app	Lesson
20	Strings	Miscellaneous	Work with the string library	Lesson
21	Regex	Miscellaneous	Work with regular epressions	Lesson
22	Goroutines	Miscellaneous	Work with goroutines and channels	Lesson
23	Database with Sqlite	Miscellaneous	Work with databases	Lesson
24	Read and write to files	IO	Learn to read from and write to files	Lesson
25	Files and directories	IO	Learn to perform operations on files and directories	Lesson

How to use this content

Every chapter consist of a lesson and an exercise. You are encouraged to run the code in the exercise, modify it and understand how it works.

Contributions

Contributions are very welcome. Please raise an issue of you see something or a PR.

I welcome contributions on:

• Suggestions on topics to cover
• Correctness issues
• Spelling
• Suggestions on better formatting
• I hope I hear from you. :)

golang-book's Issues

Structs Lesson Broken Link

When accessing the Structs page from https://softchris.github.io/golang-book/ the link returns a 404 error

Feat: previous and next buttons in the Footer

something like this

Interfaces - Wrong Code for Square Area

Hi,

You've got this code in the Implement Square section of your Interfaces lesson:

type Square struct {
  side int
}

func (s Square) area() int {
  return s.square * s.square
}

I'm pretty sure the function should return s.side * s.side, as it does further down in the Full code.

Broken links to lessons in online book

Unable to access chapter 10 (Structs) and chapter 25 (Files and Directories) due to broken links.

First Project - Wrong Function Name

In the First project lesson, you wrote:

to use the public Helper() function from main.go, we need to import it.

But the function is actually called Help().

usage of undefined variable in consume external module chapter

In the chapter consume external module of online version of the book the code example has an error where the variable sum is used without definition

package main

import (
"fmt"
"github.com/softchris/math"
)

func main() {
sum += math.Add(1,2)
fmt.Println(sum)
}

the line sum += math.Add(1,2) should be replaced with sum := math.Add(1,2)

Ch2

• Copyedit
• Add Image header
• ...other stuff

Build A Web App - Typo in Assignment Solution: func handleRequest()

• Typo observed at: https://softchris.github.io/golang-book/04-webdev/02-web-dev/
• Issue source: 04-web-dev/02-web-dev/README.md:370: func handleRequest(w http.ResponseWrite, r *http.Request) {
• Issue resolution First param, w http.ResponseWrite, should instead be w http.ResponseWriter

Create shared module - typo

In the Create shared module lesson, you have:

The uppercase variables and methods makes the publicly available.

I suppose "the" should be "them"?

Ch1:Loops section continue statement is missing.

First of all great effort for this book.

In the Chapter1 Loops section under the Controlling the loop with continue and break the continue program missing the continue statement.

Expected Output:
2,3
Actual Output:
nothing

Need to Fix:
Change the break keyword instead put continue.

Thank you @softchris

Ch1

• Copyedit
• Add Image header
• ...other stuff

Concurrency vs Parallelism

In the lesson on Goroutines and channels, you say:

Concurrency is the task of running and managing the multiple computations at the same time. While parallelism is the task of running multiple computations simultaneously.

You're essentially saying that concurrency and parallelism are the same, which I'm sure you know is not the case.

This Stack Overflow answer provides a concise explanation of the difference between them. Rob Pike's talks "Concurrency is not Parallelism" and "Go Concurrency Patterns" also discuss the topic further.