Book Image

The Go Workshop

By : Delio D'Anna, Andrew Hayes, Sam Hennessy, Jeremy Leasor, Gobin Sougrakpam, Dániel Szabó
Book Image

The Go Workshop

By: Delio D'Anna, Andrew Hayes, Sam Hennessy, Jeremy Leasor, Gobin Sougrakpam, Dániel Szabó

Overview of this book

The Go Workshop will take the pain out of learning the Go programming language (also known as Golang). It is designed to teach you to be productive in building real-world software. Presented in an engaging, hands-on way, this book focuses on the features of Go that are used by professionals in their everyday work. Each concept is broken down, clearly explained, and followed up with activities to test your knowledge and build your practical skills. Your first steps will involve mastering Go syntax, working with variables and operators, and using core and complex types to hold data. Moving ahead, you will build your understanding of programming logic and implement Go algorithms to construct useful functions. As you progress, you'll discover how to handle errors, debug code to troubleshoot your applications, and implement polymorphism using interfaces. The later chapters will then teach you how to manage files, connect to a database, work with HTTP servers and REST APIs, and make use of concurrent programming. Throughout this Workshop, you'll work on a series of mini projects, including a shopping cart, a loan calculator, a working hours tracker, a web page counter, a code checker, and a user authentication system. By the end of this book, you'll have the knowledge and confidence to tackle your own ambitious projects with Go.
Table of Contents (21 chapters)
Free Chapter
1
1. Variables and Operators
2
2. Logic and Loops

Duck Typing

We have been basically doing what is called duck typing. Duck typing is a test in computer programming: "If it looks like a duck, swims like a duck, and quacks like a duck, then it must be a duck." If a type matches an interface, then you can use that type wherever that interface is used. Duck typing is matching a type based upon methods, rather than the expected type:

type Speaker interface {
  Speak() string
}

Anything that matches the Speak() method can be a Speaker{} interface. When implementing an interface, we are essentially conforming to that interface by having the required method sets:

package main
import (
  "fmt"
)
type Speaker interface {
  Speak() string
}
type cat struct {
}
func main() {
  c := cat{}
  fmt.Println(c.Speak())
}
func (c cat) Speak() string {
  return "Purr Meow"
}

cat matches the Speak() method of the Speaker{} interface, so a cat is a Speaker...