What's the meaning of interface{}?

Question

I\'m new to interfaces and trying to do SOAP request by github

I don\'t understand the meaning of

Msg interface{}

in this code:

Answer 1

It's called the empty interface and is implemented by all types, which means you can put anything in the Msg field.

Example :

body := Body{3}
fmt.Printf("%#v\n", body) // -> main.Body{Msg:3}

body = Body{"anything"}
fmt.Printf("%#v\n", body) // -> main.Body{Msg:"anything"}

body = Body{body}
fmt.Printf("%#v\n", body) // -> main.Body{Msg:main.Body{Msg:"anything"}}

This is the logical extension of the fact that a type implements an interface as soon as it has all methods of the interface.