This is a creation in Article, where the information may have evolved or changed. Welcome to the 27th chapter of [Golang Series Tutorial] (HTTPS://STUDYGOLANG.COM/SUBJECT/2). Go does not support inheritance, but it supports combinations (composition). Combinations are generally defined as "merged together." A car is an example of a combination: A car is made up of wheels, engines, and various other components. # # through nested structures in Go, by nesting structures within the structure, you can achieve the combination. A typical example of a portfolio is a blog post. Each blog post has title, content, and author information. Use a combination to represent them well. By following this tutorial, we will know how to implement a combination. We first create a ' author ' structure. "' Gopackage mainimport (" FMT ") type author struct {firstName string LastName string Bio String}func (a author) fullName ( ) string {return FMT. Sprintf ("%s%s", A.firstname, A.lastname)} ' in the code snippet above, we created a ' author ' struct, ' Author ' field has ' firstName ', ' lastName ' and ' bio '. We have also added a ' fullName () ' method, where ' author ' is the recipient type, and the method returns the author's full name. Next we create the ' post ' structure. ' Gotype post struct {title string content string Author}func (P post) details () {FMT. Println ("Title:", P.title) fmt. Println ("Content:", p.content) fmt. Println ("Author:", P.author.fullname ()) fmt. Println ("Bio:", P.author.bio)} ' post ' struct field has ' title ' and ' content '. It also has a nested anonymous field ' author '. This field specifies that ' author ' constitutes the ' post ' structure. Now ' post ' can access all fields of ' author ' structand methods. We also added the ' details () ' method to the ' post ' structure to print the title, the content, and the author's full name and profile. Once a struct field is nested within the structure, Go allows us to access its nested fields as if the fields belonged to the external structure. So the 11th line above ' p.author.fullname () ' can be replaced with ' p.fullname () '. The ' details () ' method can then be rewritten as follows: ' Gofunc (P post) details () {FMT. Println ("Title:", P.title) fmt. Println ("Content:", p.content) fmt. Println ("Author:", P.fullname ()) fmt. Println ("Bio:", P.bio)} ' Now that our ' author ' and ' Post ' structures are ready, let's create a blog post to complete this program. "' Gopackage mainimport (" 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}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 () {author1: = author{"Naveen", "Ramanathan", "Golang Enthusiast",} post1: = post{"in Heritance in Go "," go supports composition instead of inheritance ", Author1,} Post1.detaiLS ()} "[Run on Playground] (HTTPS://PLAY.GOLANG.ORG/P/SSKWATPJGR) in the above program, the main function creates a new ' author ' struct variable on line 31st. In line 36th, we create a ' post ' by nesting ' author1 '. The program output: "' Bashtitle:inheritance in Go Content:go supports composition instead of inheritance Author:naveen Ramanathan Bi O:golang Enthusiast ' # # structure Slice nesting we can further work with this example by using a slice of a blog post to create a Web site. :) We first define the ' website ' structure. In the main function of the code above, add the following code and run it. "' Gotype website struct {[]post}func (w website) contents () {FMT. Println ("Contents of website\n") for _, V: = Range w.posts {v.details () fmt. Println ()}} "" After you add the above code, when you run the program, the compiler will error, as follows: "' Bashmain.go:31:9: Syntax error:unexpected [, expecting field name or Embedded type ' ' error indicates a nested structure slice ' []post '. The reason for the error is that the struct cannot nest an anonymous slice. We need a field name. So let's fix this error and let the compiler pass. "' Gotype website struct {posts []post} ' can see that I have added a field name ']post ' to my post's slice ' [posts '. Now let's modify the main function to create some posts for our new site. The modified complete code looks like this: "' Gopackage mainimport (" FMT ") type author struct {firstName string LastName string Bio String}func (a auth OR) FullName () string {RetuRN FMT. Sprintf ("%s%s", A.firstname, A.lastname)}type post struct {title string content string Author}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 D OES 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 ()}" [In PLAYG Run in round] (Https://play.golang.org/p/gKaa0RbeAE) in the main function above, we created an author ' Author1 ', and three posts ' post1 ', ' post2 ' and 'Post3 '. We finally created the site ' W ' in line 62nd by nesting three posts, and displayed the content on the next line. The program outputs: "' bashcontents of Websitetitle:inheritance in Go Content:go supports composition instead of inheritance author:n Aveen Ramanathan Bio:golang enthusiasttitle:struct instead of Classes in Go Content:go does not support Classes but met Hods can added to structs author:naveen Ramanathan Bio:golang enthusiasttitle:concurrency Content:go is a concurren T language and not a parallel one author:naveen Ramanathan bio:golang enthusiast ' ' This concludes this tutorial. Have a nice day. * * Previous tutorial-[struct substitution class] (https://studygolang.com/articles/12630) * * * * Next tutorial-[polymorphism] (https://studygolang.com/articles/12681) * *
Via:https://golangbot.com/inheritance
Author: Nick Coghlan Translator: Noluye proofreading: polaris1119
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