staught

通过嵌套结构体进行组合

在Go中，通过在结构体内嵌套结构体，可以实现组合。

举个典型例子，博客帖子。每一个博客的帖子都有标题、内容、作者信息。组合可以很好的表示它们。

package main

import "fmt"

type author struct {
    firstName string
    lastName  string
    bio       string
}

func (a author) fullName() string {
    return fmt.Sprintf("%s %s", a.firstName, a.lastName)
}

type post struct {
    title   string
    content string
    author // 嵌套的匿名字段
}

func (p post) details() {
    fmt.Println("Title:", p.title)
    fmt.Println("Content:", p.content)
    fmt.Println("Author:", p.fullName())
    fmt.Println("Bio:", p.bio)
}

func main() {
    // 创建一个博客帖子
    author1 := author{
        "Naveen",
        "Ramanathan",
        "Golang Enthusiast",
    }
    post1 := post{
        "Inheritance in Go",
        "Go supports composition instead of inheritance",
        author1,
    }
    post1.details()
}

结构体切片的嵌套

进一步处理，使用博客帖子的切片来创建一个网站。

package main

import "fmt"

type author struct {
    firstName string
    lastName  string
    bio       string
}

func (a author) fullName() string {
    return fmt.Sprintf("%s %s", a.firstName, a.lastName)
}

type post struct {
    title   string
    content string
    author  // 嵌套的匿名字段
}

func (p post) details() {
    fmt.Println("Title:", p.title)
    fmt.Println("Content:", p.content)
    fmt.Println("Author:", p.fullName())
    fmt.Println("Bio:", p.bio)
}

type website struct {
    posts []post
}

func (w website) contents() {
    fmt.Println("Contents of Website\n")
    for _, v := range w.posts {
        v.details()
        fmt.Println()
    }
}

func main() {
    author1 := author{
        "Naveen",
        "Ramanathan",
        "Golang Enthusiast",
    }
    post1 := post{
        "Inheritance in Go",
        "Go supports composition instead of inheritance",
        author1,
    }
    post2 := post{
        "Struct instead of Classes in Go",
        "Go does not support classes but methods can be added to structs",
        author1,
    }
    post3 := post{
        "Concurrency",
        "Go is a concurrent language and not a parallel one",
        author1,
    }
    w := website{
        posts: []post{post1, post2, post3},
    }
    w.contents()
    // output:
    /*
    Contents of Website

    Title: Inheritance in Go
    Content: Go supports composition instead of inheritance
    Author: Naveen Ramanathan
    Bio: Golang Enthusiast

    Title: Struct instead of Classes in Go
    Content: Go does not support classes but methods can be added to structs
    Author: Naveen Ramanathan
    Bio: Golang Enthusiast

    Title: Concurrency
    Content: Go is a concurrent language and not a parallel one
    Author: Naveen Ramanathan
    Bio: Golang Enthusiast
    */
}

reference:

https://studygolang.com/articles/12680