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goreflectionreflect

invoke a method from a new instance (reflect.New) with reflection

I want to instantiate an object in Go using reflection and call a method on it. However, I have no idea how to do this. I have tried something, but it does not work.

type foo struct {
    name string
}

func (f *foo) Bar() {
    f.name = "baz"
    fmt.Println("hi " + f.name)
}

func main() {
    t := reflect.TypeOf(&foo{})
    fooElement := reflect.New(t).Elem()
    fooElement.MethodByName("Bar").Call([]reflect.Value{})
}
Solution

  • reflect.New works exactly like the new function, in that it returns an allocated pointer to the given type. This means you want pass the struct, not a pointer to the struct, to reflect.TypeOf.

    t := reflect.TypeOf(foo{})
fooV := reflect.New(t)

    Since you now have a pointer value of the correct type, you can call the method directly:

    fooV.MethodByName("Bar").Call(nil)

    https://play.golang.org/p/Aehrls4A8xB