GoLang: The Ultimate Guide

366 Pages·2022·7.104 MB·English

by  Sufyan bin Uzayr

GoLang
Go, also known as GoLang, is a Google-developed open-source, compiled, and
statically typed computer language. Go is a general purpose programming lan-
guage with a straightforward syntax and a large standard library. The building of
highly accessible and scalable web apps is one of the primary areas where GoLang
is widely used. It may also be used to develop command-line programs, desktop
applications, and even mobile apps.
Go was designed from the ground up for networking and infrastructure-related
applications. It was developed as a replacement for popular server-side languages
like Java and C++. The Go programming language aims to combine the efficiency
and safety of a statically typed, compiled language with the simplicity of program-
ming of an interpreted, dynamically typed language. It also aspires to be cutting-
edge, with networked and multicore computer capabilities.
Why Should You Learn GoLang?
GoLang is becoming one of the most popular languages, which means that
learning it can open up new doors of opportunity and even help you land a job at
various companies that use Go extensively.
Ease of writing concurrent programs, fast compilation, simple syntax, and static
linking are some of the features that make Go an ideal candidate for developing
various applications.
Features:
• Step-by-step approach to problem solving and skill development
• A quick run-through of the basic concepts, in the form of a “Crash
Course”
• Advanced, hands-on core concepts, with a focus on real-world
problems
• Industry-level coding paradigm, practice-oriented explanatory
approach
• Special emphasis on writing clean and optimized code, with addi-
tional chapters focused on coding methodology
GoLang
The Ultimate Guide
Edited by
Sufyan bin Uzayr
First edition published 2023
by CRC Press
6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742
and by CRC Press
4 Park Square, Milton Park, Abingdon, Oxon, OX14 4RN
CRC Press is an imprint of Taylor & Francis Group, LLC
© 2023 Sufyan bin Uzayr
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Library of Congress Cataloging-in-Publication Data
Names: Bin Uzayr, Sufyan, author.
Title: GoLang : the ultimate guide / Sufyan bin Uzayr.
Description: First edition. | Boca Raton : CRC Press, 2023. | Includes
bibliographical references and index.
Identifiers: LCCN 2022025681 (print) | LCCN 2022025682 (ebook) |
ISBN 9781032312323 (hardback) | ISBN 9781032312316 (paperback) |
ISBN 9781003309055 (ebook)
Subjects: LCSH: Go (Computer program language)
Classification: LCC QA76.73.G63 B56 2023 (print) | LCC QA76.73.G63
(ebook) | DDC 005.13/3--dc23/eng/20220919
LC record available at https://lccn.loc.gov/2022025681
LC ebook record available at https://lccn.loc.gov/2022025682
ISBN: 9781032312323 (hbk)
ISBN: 9781032312316 (pbk)
ISBN: 9781003309055 (ebk)
DOI: 10.1201/9781003309055
Typeset in Minion
by KnowledgeWorks Global Ltd.
Contents
Acknowledgments, xix
About the Author, xxi
Chapter 1 ◾ C rash Course in GoLang 1
IS IT REFERRED TO AS Go OR GoLang? 2
WHAT IS THE PURPOSE OF GoLang? 2
WHY IS Go SO POPULAR? 2
Other Programming Languages vs. Go 3
Python vs. Go 3
But How Does Go Stack Up against Python? 3
SHOULD WE STUDY Go? 4
Go PROGRAMMING FEATURES 4
WHAT MAKES GoLang SUPERIOR TO OTHER
COMPUTER LANGUAGES? 5
GoLang’s Core Capability 5
Multithreading and Concurrency 6
From within, Go Empowers Hardware 6
Unmatched Simplicity of Go 7
Built-in Testing and Profiling Framework 7
Easy Learning Curve 7
BEGINNING WITH Go 8
Text Editor 8
Finding a Go Compiler 8
v
vi ◾ Contents
INSTALL Go ON WINDOWS 8
How Can We Know Which Go Language Version Is
Preinstalled? 9
Downloading and Installing Go 9
WRITING THE FIRST Go PROGRAM 10
Why Is There a “Go Language”? 11
What Is Missing in Go That the Other Languages Have? 11
Hardware Restrictions 12
The Upsides and Downsides of the Go Language 12
TERMINAL 13
The Open Terminal Tool Window 13
Start the New Session 14
INSTALL Go ON Mac 14
Making Our First Program 16
Implement a Go Program 16
Do Go Programs Interact with Programs Written in C/C++? 17
HOW CAN WE CREATE AN EMPTY FILE IN GoLang? 17
HOW TO MAKE A DIRECTORY IN Go 19
HOW TO READ AND WRITE A Go PROGRAM 20
HOW DO WE RENAME AND TRANSFER A FILE
IN GoLang? 23
HOW TO READ A FILE LINE BY LINE AND CONVERT
IT TO A STRING 24
BASIC SYNTAX 25
Tokens 25
Line Separator 25
Comments 25
Identifiers 26
Keywords 26
Whitespace 27
DATA TYPES IN Go 27
Numbers 28
Contents ◾ vii
Booleans 30
Strings 30
VARIABLES IN Go 31
Declaring a Variable 32
Employing the var Keyword 32
Using the Short Variable Declaration 35
CONSTANTS 38
How Should We Declare? 39
Untyped and Typed Numeric Constants 39
Numeric Constant 39
String Literals 41
Boolean Constant 42
VARIABLE SCOPE IN Go 43
Local Variables 43
Global Variables 44
DECLARATION OF MULTIPLE VARIABLES 46
SHORTHAND DECLARATION 48
OPERATORS IN Go 49
Arithmetic Operators 50
Relational Operators 51
Logical Operators 53
Bitwise Operators 53
Assignment Operators 54
Misc Operators 56
CONTROL STATEMENTS 57
if Statement 57
if…else Statement 58
Nested if Statement 60
if..else..if Ladder 61
SWITCH STATEMENT 63
Expression Switch 63
Type Switch 64
viii ◾ Contents
ARRAYS 65
Creating and Using an Array 65
Using var Keyword 65
Using a Shorthand Declaration 66
Multidimensional Array 67
How Do You Copy an Array into Another Array? 68
How Can We Pass an Array to a Function? 69
SLICES 70
Slice Declaration 70
Slice Components 71
How Do We Create and Begin a Slice? 72
Using Slice Literal 72
Using an Array 72
Using an Existing Slice 73
Using the make() Function 74
How to Iterate over a Slice 75
Using the for Loop 75
Using Range in a for Loop 76
Using a Blank Identifier in a for Loop 76
Slice Composite Literal 77
How to Sort a Slice of ints 77
Ints 78
IntsAreSorted 78
How Do We Trim a Slice of Bytes in GoLang? 79
How Do We Split a Slice of Bytes? 81
STRING 82
String Literals 83
Using Double Quotes (“”) 83
Using Backticks(“) 83
How Do We Trim a String? 84
Trim 84
TrimLeft 85
Contents ◾ ix
TrimRight 86
TrimSpace 87
TrimSuffix 88
TrimPrefix 89
How to Split a String 90
Split 90
SplitAfter 91
SplitAfterN 92
MAPS 93
How Do We Create and Initialize Maps? 94
Simple 94
Using the make() Function 95
WHAT IS A BLANK IDENTIFIER (underscore)? 96
DEFER KEYWORD 97
PANIC IN GoLang 98
RECOVER 99
CLOSURES 100
RECURSION 101
POINTERS 102
What Are Points Used For? 102
Pointers Declaration and Initialization 103
Declaring a Pointer 103
Pointer Initialization 103
Dereferencing a Pointer 104
In GoLang, How Can We Instantiate a Struct Using the
New Keyword? 105
Pointers to a Function 106
Create a Pointer and Pass It to the Function 106
Passing an Address of the Variable to Function Call 107
Pointer to a Struct 108
Pointer to Pointer in Go 109
How to Declare a Pointer to a Pointer 109