Mastering Golang. A Beginner's Guide

Cover....1

Half Title....2

Series Page....3

Title Page....4

Copyright Page....5

Contents....6

Preface....16

About the Author....18

CHAPTER 1: Getting Started with Go....20

GO PROGRAMMING FEATURES....20

WHY IS GoLang BETTER THAN THE OTHER PROGRAMMING LANGUAGES?....21

GoLang’s Core Capability....21

Multithreading and Concurrency....22

Go Empowers Hardware from Within....23

The Unmatched Simplicity of Go....23

Inbuilt Testing and Profiling Framework....23

Easy Learning Curve....24

BEGINNING WITH Go....24

Text Editor....24

Finding a Go Compiler....24

INSTALL Go ON WINDOWS....25

How Do We Determine the Go Language Version That Is Preinstalled?....25

Downloading and Installing Go....25

WRITING THE FIRST Go PROGRAM....26

Single-Line Comment....27

Multiline Comment....27

Explanation of the Preceding Program....27

Why Is There a “Go Language”?....28

What Is Absent in Go That Is Present in Other Languages?....28

Hardware Restrictions....28

Benefits and Drawbacks of the Go Language....28

TERMINAL....29

The Open Terminal Tool Window....30

Start New Session....30

INSTALL Go ON MAC....30

Making Our First Program....32

Execute a Go Program....33

Do Programs in Go Link with the C/C++ Programming Language?....33

IN GoLang, HOW DO WE CREATE AN EMPTY FILE?....34

In GoLang, We May Check Whether a Given File Exists or Not....35

CREATE A DIRECTORY IN Go....37

Make a Single Directory....37

Make a Directory Hierarchy (Nested Directories)....37

CHAPTER 2: GoLang Tools....40

HOW TO READ AND WRITE PROGRAMS IN Go....40

IN GoLang, HOW TO RENAME AND MOVE A FILE....45

HOW TO READ FILES LINE BY LINE TO STRING....46

CHAPTER 3: Data Types....48

BASIC SYNTAX....48

Tokens....48

Line Separator....49

Comments....49

Identifiers....49

Keywords....51

Whitespace....51

DATA TYPES IN Go....52

Numbers....52

Floating Point Numbers....53

Complex Numbers....53

Booleans....54

Strings....55

CHAPTER 4: Variables and Constants....56

VARIABLES IN Go....56

Declaring a Variable....57

Using the var Keyword....57

Using the Short Variable Declaration....60

CONSTANTS....64

How Should We Declare?....64

Untyped and Typed Numeric Constants....64

Numeric Constant....65

String Literals....66

Boolean Constant....67

VARIABLE SCOPE IN Go....68

Local Variables....68

Global Variables....69

DECLARATION OF MULTIPLE VARIABLES....71

Shorthand Declaration....73

CHAPTER 5: Operators and Control Structures....76

OPERATORS IN Go....76

Arithmetic Operators....77

Relational Operators....78

Logical Operators....79

Bitwise Operators....80

Assignment Operators....81

Misc Operators....83

CONTROL STATEMENTS....84

if Statement....85

if…else Statement....86

Nested if Statement....88

if..else..if Ladder....89

Go LANGUAGE LOOPS....91

Go SWITCH STATEMENT....96

Expression Switch....97

Type Switch....99

CHAPTER 6: Arrays, Slices, and Maps....102

ARRAYS....102

Creating and Accessing an Array....102

Using the var Keyword....103

Using a Shorthand Declaration....104

Multidimensional Array....105

Important Observations about the Array....106

In GoLang, How Do We Copy an Array into Another Array?....109

In GoLang, How Can We Pass an Array to a Function?....111

SLICES....112

Slice Declaration....112

Slice Components....113

How Can We Create and Initialize a Slice?....114

Using the Slice Literal....114

Using an Array....115

Using an Existing Slice....115

Using the make() Function....116

How to Iterate over a Slice....117

Using the for loop....118

Using Range in the for loop....118

Using a Blank Identifier in a for loop....119

Important Points about Slice....119

Zero Value Slice....119

Modifying Slices....119

Slice Comparison....120

Multidimensional Slice....121

Sorting of Slice....121

Slice Composite Literal....122

In GoLang, How Do We Sort a Slice of Ints?....123

Ints....123

IntsAreSorted....124

In GoLang, How Can You Trim a Slice of Bytes?....125

How Can You Split a Slice of Bytes in GoLang?....127

STRINGS....129

String Literals....130

Using Double Quotes("")....130

Using backticks(")....130

Important Points about Strings....131

Strings Are Immutable....131

How to Iterate over a String....132

How to Access an Individual Byte of the String....133

How to Make a String from a Slice of Bytes....133

How Can We Determine the Length of a String in GoLang?....134

In GoLang, How Do We Trim a String?....134

Trim....134

TrimLeft....135

TrimRight....136

TrimSpace....137

TrimSuffix....138

TrimPrefix....139

In GoLang, How Do We Split a String?....140

Split....140

SplitAfter....141

SplitAfterN....143

In GoLang, There Are Several Ways to Compare Strings....144

Making Use of Comparison Operators....144

Using Compare() Method....145

MAPS....146

How Do We Create and Initialize Maps?....147

Simple....147

Using the make() Function....148

Important Considerations....149

How Do We Iterate over a Map?....149

How to Add Key-Value Pairs to the Map....150

How to Retrieve the Value Associated with a Key in a Map....151

How to Check If the Key Is Present on the Map....151

How to Remove a Key from a Map....152

Map Modification....153

CHAPTER 7: Functions and Recursion....156

Go LANGUAGE FUNCTIONS....156

Function Declaration....156

Function Calling....157

Function Arguments....158

Call by Value....158

Call by Reference....159

FUNCTION RETURNING MULTIPLE VALUES....160

Giving Names to the Return Values....160

VARIADIC FUNCTIONS....161

Anonymous Functions....163

GoLang main() and init() Functions....166

main() Function....166

init() Function....167

In GoLang, What Is a Blank Identifier (Underscore)?....168

DEFER KEYWORD....169

PANIC IN GoLang....172

Panic’s Usage....175

RECOVER....175

Quick Points....176

CLOSURE....177

RECURSION....179

Recursion Types....180

Direct Recursion....181

Indirect Recursion....182

Tail Recursion....183

Head Recursion....184

Infinite Recursion....185

Anonymous Function Recursion....185

CHAPTER 8: Pointers....190

GoLang POINTERS....190

What Is the Purpose of a Pointer?....190

Declaration and Initialization of Pointers....192

Declaring a Pointer....192

Pointer Initialization....192

Important Considerations....193

Dereferencing Pointer....195

In GoLang, How Can We Instantiate a Struct Using the New Keyword?....196

POINTERS TO A FUNCTION....197

Create a Pointer and Pass It to the Function....197

Passing an Address of the Variable to Function Call....198

POINTER TO A STRUCT....199

POINTER TO POINTER (DOUBLE POINTER) IN Go....201

How to Declare a Pointer to a Pointer....201

COMPARING POINTERS....203

CHAPTER 9: Structs and Interfaces....206

GoLang STRUCTURES....206

How Can We Get to Struct Fields?....208

Pointers to a Struct....209

GoLang’s NESTED STRUCTURE....210

GoLang’s ANONYMOUS STRUCTURE AND FIELD....212

Anonymous Structure....212

Anonymous Fields....213

GoLang METHODS....215

Method with the Struct Type Receiver....215

Method with the Non-Struct Type Receiver....216

Methods with the Pointer Receiver....217

Method Can Accept Both the Pointer and the Value....218

Difference between the Method and the Function....219

INTERFACES....219

How Do We Make an Interface?....220

How to Implement Interfaces....220

Why Go Interfaces Are Great....225

Redundant Functions....225

Enter Interface....227

EMBEDDING INTERFACES....228

INHERITANCE....234

POLYMORPHISM USING INTERFACES....237

CHAPTER 10: Concurrency and Goroutines....240

GOROUTINES – CONCURRENCY IN GoLang....240

Go Concurrent Programming....241

Issues with Multithreading....241

Concurrent Programming in Go....242

How to Handle Concurrency Issues in Go....242

Goroutine with WaitGroup Example....242

How to Create a Goroutine....243

Anonymous Goroutines....245

SELECT STATEMENT....246

MULTIPLE GOROUTINES....250

GoLang CHANNEL....252

Creating a Channel....252

Send and Receive Data from a Channel....253

Send Operation....253

Receive Operation....253

Channel Closing....254

UNIDIRECTIONAL CHANNEL....258

Converting a Bidirectional Channel to a Unidirectional Channel....259

CHAPTER 11: Packages in GoLang....260

PACKAGES IN GoLang....260

Workspace....260

Packages....261

Main Package....261

Importing Packages....262

Installing Third-Party Packages....262

Init Function....262

Important Considerations....264

Giving the Packages Names....265

Code Exported....267

DOCUMENTATION....269

CHAPTER 12: The Core Packages....270

STRING....271

INPUT/OUTPUT (I/O)....272

FILES AND FOLDERS....272

ERRORS....275

CONTAINERS AND SORTING....275

List....275

SORT....276

HASHES AND CRYPTOGRAPHY....277

SERVERS....279

HTTP....281

RPC....282

PARSING THE COMMAND LINE ARGUMENTS....283

SYNCHRONIZATION PRIMITIVES....284

Mutexes....284

APPRAISAL....286

BIBLIOGRAPHY....290

INDEX....294

Mastering GoLang helps readers quickly understand the core concepts and then move on to practical projects using the Go programming language.

GoLang is often dubbed a game-changer in the world of programming languages. Instead of starting from scratch, Go was created using the C programming language. GoLang inherits C’s disciplined grammar but with specific tweaks and enhancements to properly manage memory. This lessens the memory leakage problems that developers tend to face with C.

Go borrows and adapts notions from various programming languages while skipping characteristics that result in complicated, insecure, and unpredictable code. Go’s concurrency features are well-suited to build the infrastructure for gigantic projects such as networking systems and distributed hardware. Go is also often employed in domains such as visuals, mobile applications, and Machine Learning.

Even though GoLang is a relatively new language, it has been adopted by several major organizations owing to its benefits, which include code clarity, custom libraries, adaptability, multithreading, and a simple build process. Because Go is gaining traction in the development community, learning GoLang can open up new avenues across various fields and career trajectories.

Since it is still a relatively newer language, quality literature pertaining to Go is often hard to find. This particular book covers all the bases that you might need, and is an ideal companion for beginner-level developers looking to master Go programming.

With Mastering GoLang, learning GoLang becomes an easy task, and learners can use their skills to create innovative projects.

The Mastering Computer Science series is edited by Sufyan bin Uzayr, a writer and educator with over a decade of experience in the computing field.