Interfaces

Interfaces are a way to define a set of methods that a type must implement. This allows you to define a function that can take any type that implements the interface. This is similar to duck typing in Python. Interfaces are defined as a set of method signatures.

// [...]

// Area Interface
type Area interface {
    Area() float64
}

// Different Structs
type Rectangle struct {
    Width  float64
    Height float64
}

type Circle struct {
    Radius float64
}

// Add Area() function to structs
func (c Circle) Area() float64 {
    return 3.14 * math.Pow(c.Radius, 2)
}

func (r Rectangle) Area() float64 {
    return r.Width * r.Height
}

// main calc function
func calcArea(obj Area) float64 {
    return obj.Area()
}

func main() {
    r := Rectangle{
        Width:  10,
        Height: 4,
    }
    c := Circle{
        Radius: 12,
    }
    rArea := calcArea(r)
    cArea := calcArea(c)
}

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