why is this method definition syntax accepted in Go?

Question

the code

package main

import "fmt"

type unimplementedGreeterServer struct {
}

func (unimplementedGreeterServer) SayHello() string {
    return "hello"
}

func main() {
    s := &unimplementedGreeterServer{}
    ret := s.SayHello()
    fmt.Println(ret)
}

the result

hello

the question : why the SayHello method has no unimplementedGreeterServer point or unimplementedGreeterServer receiver can run

I think the right will be

func (s unimplementedGreeterServer) SayHello2() string {
    return "hello"
}

func (s *unimplementedGreeterServer) SayHello3() string {
    return "hello"
}

not

func (unimplementedGreeterServer) SayHello() string {
    return "hello"
}

score 3 · Accepted Answer · answered Nov 21 '21 at 03:10

3

The receiver itself is optional. If the method does not use the receiver, you can omit it. The declaration:

func (unimplementedGreeterServer) SayHello() string {
    return "hello"
}

simply defines a method for unimplementedGreeterServer that does not use the receiver. It is defined for a value receiver, so it is defined for unimplementedGreeterServer and *unimplementedGreeterServer.

answered Nov 21 '21 at 03:10

Burak Serdar

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any document about it ? – fuyou001 Nov 21 '21 at 03:24
The go language specification describes the blank receiver: https://golang.org/ref/spec#Method_declarations – Burak Serdar Nov 21 '21 at 03:34

why is this method definition syntax accepted in Go?

1 Answers1