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This article is about how Go implements the interface interface through the structure struct. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

1. Implement the interface through struct (interface)

1. When you understand the iris framework, you often see that it is written to use an empty structure as a receiver to call a method. I wonder what it makes sense to do so.

Explanation: in the Go language, a struct implements all the methods in an interface, and it is called the struct that implements the interface.

2. The empty structure has the following characteristics.

A. do not occupy memory address.

B. the address remains the same.

3. First of all, we know that interface defines abstract methods, and the following func is its concrete implementation (which is similar to java), but we know that there is no way to instantiate interface in java because it is abstract. So the purpose of this operation is: first, the NewEntraceRepository method returns a pointer to an empty structure (the empty structure must implement the current interface), and then we can call the current interface method directly using the variables created by NewEntraceRepository.

Func NewEntraceRepository () EntraceRepository {return & entraceRepository {;}

The above code is equivalent to the following

Var variable_value EntraceRepository=&entraceRepository {}

Question: why can this empty structure be assigned to interface? we know that only structures that implement all the methods of interface can be assigned this way.

Func (n bookRepository) GetBookList (m map [string] interface {}) (total int,books [] models.Book) {}

In fact, a struct implements all the methods in an interface, and it is called the struct that implements the interface. So using a variable to receive this address can be called directly.

Let's write a Demo implementation, first write a Study interface {}, which needs to implement four methods Listen, Speak, Read, Write, and then write a study struct {} to implement all the methods, and then share the code experience.

II. Code example / / Go-structure (struct) implementation interface (interface) package main import ("fmt"github.com/pkg/errors") var _ Study = (* study) (nil) type Study interface {Listen (msg string) string Speak (msg string) string Read (msg string) string Write (msg string) string} type study struct {Name string} func (s * study) Listen (msg string) string {return s.Name + " Listen to + msg} func (s * study) Speak (msg string) string {return s.Name + "say" + msg} func (s * study) Read (msg string) string {return s.Name + "read" + msg} func (s * study) Write (msg string) string {return s.Name + "write" + msg} func New (name string) (Study Error) {if name = = "{return nil, errors.New (" name required ")} return & study {Name: name,}, nil} func main () {name: =" Xiao Ming "s Err: = New (name) if err! = nil {fmt.Println (err)} fmt.Println (s.Listen ("english")) fmt.Println (s.Speak ("english")) fmt.Println (s.Read ("english")) fmt.Println (s.Write ("english"))} Thank you for reading! This is the end of the article on "how Go implements interface interface through structural struct". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it out for more people to see!

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