Can a struct in Go implement multiple interfaces at once?

Yes, in Go a struct can implement multiple interfaces at once. In Go, interface implementation is implicit: if a struct contains all the methods of an interface, it is considered to implement that interface.

This means that if a struct implements methods for multiple interfaces, it automatically implements all of those interfaces simultaneously.

Example:

package main

import "fmt"

type Reader interface {
    Read() string
}

type Writer interface {
    Write(string)
}

type ReadWriter interface {
    Reader
    Writer
}

type MyStruct struct {
    data string
}

func (m *MyStruct) Read() string {
    return m.data
}

func (m *MyStruct) Write(s string) {
    m.data = s
}

func main() {
    var rw ReadWriter = &MyStruct{}
    rw.Write("Hello")
    fmt.Println(rw.Read()) // Output: Hello
}

Here, MyStruct implements the Reader and Writer interfaces, and therefore also the ReadWriter interface.