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

interface{} means you can put value of any type, including your own custom type. All types in Go satisfy an empty interface (interface{} is an empty interface).
In your example, Msg field can have value of any type.

Example:

package main

import (
    "fmt"
)

type Body struct {
    Msg interface{}
}

func main() {
    b := Body{}
    b.Msg = "5"
    fmt.Printf("%#v %T \n", b.Msg, b.Msg) // Output: "5" string
    b.Msg = 5

    fmt.Printf("%#v %T", b.Msg, b.Msg) //Output:  5 int
}

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