What does this print? (no virtual dispatch with embedding)

type Base struct{}

func (Base) Name() string       { return "Base" }
func (b Base) Greet() string    { return "Hello from " + b.Name() }

type Derived struct{ Base }

func (Derived) Name() string { return "Derived" }

func main() {
    d := Derived{}
    fmt.Println(d.Name())  // ?
    fmt.Println(d.Greet()) // ?
}

Output:

Derived
Hello from Base

d.Name() resolves to Derived.Name, the shallowest method with that name. d.Greet() is promoted and becomes d.Base.Greet(). Inside Greet, b is a Base, and b.Name() is bound statically to Base.Name. Go has no vtable that lets an embedded type call "overridden" methods of the type that embeds it.

To get template-method behaviour, pass the behaviour in explicitly with an interface field or function:

type Namer interface{ Name() string }

func Greet(n Namer) string { return "Hello from " + n.Name() }

fmt.Println(Greet(Derived{})) // Hello from Derived

The interviewer is checking whether you carry OOP inheritance habits into Go.