If you haven’t already, I’d highly recommend my interface and struct first.
Animal, Dog & Cat
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type Animal interface {
Name() string
Sound() string
}
type Dog struct {
name string
}
func (d *Dog) Name() string {
return d.name
}
func (d *Dog) Sound() string {
return "woof"
}
func (d *Dog) Custom() string {
return "mailman? woof! woof! woof!"
}
type Cat struct {
name string
}
func (c *Cat) Name() string {
return c.name
}
func (c *Cat) Sound() string {
return "meow"
}
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Now, the difference between my interface example, and the above is Dog has a Custom function…
BUT
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import (
"fmt"
"reflect"
)
func main() {
var a Animal = &Dog{name: "Spot"}
fmt.Printf("%s says %s\n", a.Name(), a.Sound())
// We can't use Dog.Custom until we convert the Animal
// BUT, let's pretend we didn't know a's type was *Dog
switch (reflect.TypeOf(a).Name()) { // Reflect the type of a, and get it's name
case "*Dog": // If it's a Pointer to a Dog
var d *Dog = a.(*Dog) // Convert
fmt.Println(d.Custom())
default: // It's something else
fmt.Printf("Not a *Dog, it's a '%s'\n", reflect.TypeOf(a).Name())
}
}
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