Lesson 3: Two Dogs - Structs and Methods

Two Dogs Build two independent values from one struct.

1package main

3import "fmt"

5type Dog struct {

6 name string

9func main() {

10 rex := Dog{name: "Rex"}

11 bella := Dog{name: "Bella"}

12 fmt.Println(rex.name)

13 fmt.Println(bella.name)

14}

Terminal

$ go run main.go

Rex

Bella

Every line, explained

package main: Every Go file starts by saying which package it belongs to, exactly as in Intro to Go.
import "fmt": import "fmt" brings in the printing tools, as always.
type Dog struct {: type Dog struct { ... } defines a struct: a bundle of fields that belong together. Go has no classes; structs are how Go groups data, and they do the job beautifully.
name string: The blueprint says every Dog has a name.
}: This } closes the struct definition.
func main() {: func main() { ... } is where the program starts.
rex := Dog{name: "Rex"}: One struct definition...
bella := Dog{name: "Bella"}: ...as many values as you like. Think of one house plan and a whole street of houses. bella's name field is completely separate from rex's.
fmt.Println(rex.name): fmt.Println(...) prints to the terminal, exactly as in Intro to Go.
fmt.Println(bella.name): fmt.Println(...) prints to the terminal, exactly as in Intro to Go. Two values, two different names.
}: This } closes func main.