What are interfaces in Go and how do I use them?

What are interfaces in Go and how do I use them?

Interfaces in Go are types that specify a contract by defining methods. Any type that implements those methods satisfies the interface.

Can you give me an example of an interface in Go?

Sure! Here's a simple example:

type Shape interface {
    Area() float64
}

type Circle struct {
    Radius float64
}

func (c Circle) Area() float64 {
    return math.Pi * c.Radius * c.Radius
}

In this example, Shape is an interface with a method Area, and Circle implements that interface.

How do I implement multiple interfaces in a single struct?

You can implement multiple interfaces by defining all the required methods in your struct. For example:

type Shape interface {
    Area() float64
}

type Colorful interface {
    Color() string
}

type Circle struct {
    Radius float64
    ColorValue string
}

func (c Circle) Area() float64 {
    return math.Pi * c.Radius * c.Radius
}

func (c Circle) Color() string {
    return c.ColorValue
}

Here, Circle implements both Shape and Colorful interfaces.