package main

import "fmt"

type Integer int

// 面向对象

func (a Integer) Less(b Integer) bool {

    return a < b

}

// 面向过程

func Integer_Less(a Integer, b Integer) bool {

    return a < b

}

func main() {

    var a Integer = 1

    if a.Less(2) {

        fmt.Println(a, "Less 2") // 1 Less 2

    }

    if Integer_Less(a, 2) {

        fmt.Println(a, "Less 2") // 1 Less 2

    }

}

package main

import "fmt"

type Integer int

func (a *Integer) Add1(b Integer) {

    *a += b

}

func (a Integer) Add2(b Integer) {

    a += b

}

func main() {

    var a, b Integer = 2, 7

    a.Add2(b)

    fmt.Println(a, b) // 2, 7

    a.Add1(b)

    fmt.Println(a, b) // 9, 7

}

package main 

import "fmt"

type Rect struct {

    width, height float64

}

func (r *Rect) Area() float64 {

    return r.width * r.height

}

func main() {

    // 创建的几种方式

    rect1 := &Rect{100, 50}

    rect2 := &Rect{width: 100, height: 200}

    rect3 := new(Rect)

    rect3.height, rect3.width = 90, 20

    rect4 := &Rect{}

    rect4.height, rect4.width = 90, 20

    fmt.Println(rect1.Area()) //

    fmt.Println(rect2.Area()) //

    fmt.Println(rect3.Area()) //

    fmt.Println(rect4.Area()) //

}

package main 

import "fmt"

// 定义一个接口Men

type Men interface {

    sayHello()

}

type Sing interface {

    sing(name string)

}

// 接口的组合

type MenAndSing interface {

    Sing

    Men

}

type Human struct {

    name, address string

    age int

}

type Person struct {

    Human

    phone string

}

// Huamn实现了sayHello方法

func (human Human)sayHello() {

    fmt.Println("human say hello")

}

// Huamn实现了sing方法

func (human Human)sing(name string) {

    fmt.Println("human sing a song named ", name)

}

// Person重写方法

func (p Person)sayHello() {

    fmt.Println("Person say Hello")

}

func main() {

    mark := Human{"huhx", "address", 45}

    var men Men = mark

    men.sayHello() // 

    var sing Sing = mark // 由于Human实现了Sing的sing方法

    sing.sing("huhx")

    var men2 Men = Person{mark, "15527100207"}

    men2.sayHello()

    var menAdnstring MenAndSing = mark

    menAdnstring.sayHello()

    menAdnstring.sing("huhx")

}