Go Programming Language For Dummies

Wei-Meng Lee is founder of Developer Learning Solutions, specializing in hands-on technology training. His name regularly appears in publications like DevX.com, MobiForge.com, and CODE Magazine. He is also the author of SwiftUI For Dummies, Beginning Swift Programming, Python Machine Learning, and Learning WatchKit Programming.

• Introduction 1About This Book 1Foolish Assumptions 2Icons Used in This Book 2Beyond the Book 3Where to Go from Here 3Part 1: Getting Started with Go 5Chapter 1: Hello, Go! 7Seeing What Learning Go Can Do for You 8Installing Go on Your Machine 9macOS 10Windows 11Using an Integrated Development Environment with Go 12Writing Your First Go Program 14Compiling and running the program 15Understanding how a Go program works 17Making sense of the Go file structure 18Compiling for multiple operating systems 19Comparing Go with Other Languages 21Syntax 21Compilation 22Concurrency 22Library support 22Chapter 2: Working with Different Data Types 23Declaring Always-Changing Variables 24Using the var keyword: Type-inferred variables 24Specifying the data type: Explicitly typed variables 25Using the short variable declaration operator 26Declaring Never-Changing Constants 27Removing Unused Variables 27Dealing with Strings 29Performing Type Conversions 30Discovering the type of a variable 31Converting a variable’s type 32Interpolating strings 34Chapter 3: Making Decisions 37Using If/Else Statements to Make Decisions 37Laying the foundation for the if/else statement: Logical and comparison operators 38Using the if/else statement 40Short-circuiting: Evaluating conditions in Go 42When You Have Too Many Conditions: Using the Switch Statement 46Switching with fall-throughs 47Matching multiple cases 48Switching without condition 48Chapter 4: Over and Over and Over: Using Loops 51Performing Loops Using the for Statement 51Iterating over a Range of Values 56Iterating through arrays/slices 56Iterating through a string 58Using Labels with the for Loop 59Chapter 5: Grouping Code into Functions 65Defining a Function 65Defining functions with parameters 66Defining functions with multiple parameters 68Passing arguments by value and by pointer 68Returning values from functions 71Naming return values 72Working with variadic functions 72Using Anonymous Functions 73Declaring an anonymous function 73Implementing closure using anonymous functions 74Implementing the filter() function using closure 76Part 2: Working with Data Structures 79Chapter 6: Slicing and Dicing Using Arrays and Slices 81Arming Yourself to Use Arrays 81Declaring an array 82Initializing an array 83Working with multidimensional arrays 83Sleuthing Out the Secrets of Slices 86Creating an empty slice 86Creating and initializing a slice 88Appending to a slice 88Slicing and Ranging 92Extracting part of an array or slice 92Iterating through a slice 95Making copies of an array or slice 95Inserting an item into a slice 97Removing an item from a slice 99Chapter 7: Defining the Blueprints of Your Data Using Structs 101Defining Structs for a Collection of Items 101Creating a Go Struct 104Making a Copy of a Struct 105Defining Methods in Structs 107Comparing Structs 110Chapter 8: Establishing Relationships Using Maps 113Creating Maps in Go 113Initializing a map with a map literal 115Checking the existence of a key 115Deleting a key 116Getting the number of items in a map 116Iterating over a map 117Getting all the keys in a map 117Setting the iteration order in a map 118Sorting the items in a map by values 118Using Structs and Maps in Go 121Creating a map of structs 121Sorting a map of structs 124Chapter 9: Encoding and Decoding Data Using JSON 129Getting Acquainted with JSON 129Object 130String 130Boolean 131Number 131Object 132Array 132null 133Decoding JSON 134Decoding JSON to a struct 135Decoding JSON to arrays 136Decoding embedded objects 137Mapping custom attribute names 140Mapping unstructured data 141Encoding JSON 144Encoding structs to JSON 144Encoding interfaces to JSON 148Chapter 10: Defining Method Signatures Using Interfaces 151Working with Interfaces in Go 152Defining an interface 152Implementing an interface 153Looking at How You May Use Interfaces 154Adding methods to a type that doesn’t satisfy an interface 158Using the Stringer interface 159Implementing multiple interfaces 160Using an empty interface 161Determining whether a value implements a specific interface 162Part 3: Multitasking in Go 163Chapter 11: Threading Using Goroutines 165Understanding Goroutines 166Using Goroutines with Shared Resources 168Seeing how shared resources impact goroutines 168Accessing shared resources using mutual exclusion 171Using atomic counters for modifying shared resources 172Synchronizing Goroutines 174Chapter 12: Communicating between Goroutines Using Channels 179Understanding Channels 179How channels work 180How channels are used 183Iterating through Channels 186Asynchronously Waiting on Channels 187Using Buffered Channels 192Part 4: Organizing Your Code 195Chapter 13: Using and Creating Packages in Go 197Working with Packages 197Creating shareable packages 200Organizing packages using directories 202Using Third-Party Packages 204Emojis for Go 204Go Documentation 205Chapter 14: Grouping Packages into Modules 211Creating a Module 211Testing and Building a Module 214Publishing a Module on GitHub 216Part 5: Seeing Go in Action 223Chapter 15: Consuming Web APIs Using Go 225Understanding Web APIs 225Fetching Data from Web Services in Go 226Writing a Go program to connect to a web API 227Decoding JSON data 229Refactoring the code for decoding JSON data 233Fetching from multiple web services at the same time 238Returning Goroutine’s results to the main() function 239Chapter 16: Getting Ready to Serve Using REST APIs 243Building Web Services Using REST APIs 243HTTP messages 244REST URLs 244REST methods 246REST response 248Creating a REST API in Go 249Getting your REST API up and running 249Testing the REST API 251Registering additional paths 251Passing in query string 254Specifying request methods 255Storing the course information on the REST API 257Testing the REST API again 267Chapter 17: Working with Databases 271Setting Up a MySQL Database Server 272Interfacing with the MySQL server 272Creating a database and table 274Creating a new account and granting permission 275Connecting to the MySQL Database in Go 276Retrieving a record 278Adding a record 280Modifying a record 281Deleting a record 283Part 6: The Part of Tens 285Chapter 18: Ten Useful Go Packages to Create Applications 287color 287Installation 288Code sample 288now 288Installation 288Code sample 288go-pushbullet 289Installation 289Code sample 289goid 290Installation 290Code sample 290json2go 291Installation 291Code sample 291gojq 292Installation 293Code sample 293turtle 294Installation 294Code sample 294go-http-client 295Installation 295Code sample 295notify 296Installation 296Code sample 296gosx-notifier 297Installation 297Code sample 297Chapter 19: Ten Great Go Resources 299The Official Go Website 299Go by Example 300A Tour of Go 300The Go Frequently Asked Questions 300The Go Playground 300Go Bootcamp 301Effective Go 301Gophercises 301Tutorialspoint 301Stack Overflow 302Index 303