Example of Go language interface usage

This article illustrates the use of interfaces in the Go language. Share with you for your reference. The specific analysis is as follows:

An interface type is a collection defined by a set of methods.
The value of the interface type can hold any value that implements these methods.

package main

import (

    "fmt"

    "math"

)

type Abser interface {

    Abs() float64

}

func main() {

    var a Abser

    f := MyFloat(-math.Sqrt2)

    v := Vertex{3, 4}

    a = f  // a MyFloat implements Abser

    a = &v // a *Vertex implements Abser

    a = v  // a Vertex, does NOT

           // implement Abser

    fmt.Println(a.Abs())

}

type MyFloat float64

func (f MyFloat) Abs() float64 {

    if f < 0 {

        return float64(-f)

    }

    return float64(f)

}

type Vertex struct {

    X, Y float64

}

func (v *Vertex) Abs() float64 {

    return math.Sqrt(v.X*v.X + v.Y*v.Y)

}

I hope this article has been helpful to your programming of Go language.