golang interface

type Human struct {
	name string
	age int
	phone string
}

type Student struct {
	Human //匿名字段Human
	school string
	loan float32
}

type Employee struct {
	Human //匿名字段Human
	company string
	money float32
}

//Human对象实现Sayhi方法
func (h *Human) SayHi() {
	fmt.Printf("Hi, I am %s you can call me on %s\n", h.name, h.phone)
}

// Human对象实现Sing方法
func (h *Human) Sing(lyrics string) {
	fmt.Println("La la, la la la, la la la la la...", lyrics)
}

//Human对象实现Guzzle方法
func (h *Human) Guzzle(beerStein string) {
	fmt.Println("Guzzle Guzzle Guzzle...", beerStein)
}

// Employee重载Human的Sayhi方法
func (e *Employee) SayHi() {
	fmt.Printf("Hi, I am %s, I work at %s. Call me on %s\n", e.name,
		e.company, e.phone) //此句可以分成多行
}

//Student实现BorrowMoney方法
func (s *Student) BorrowMoney(amount float32) {
	s.loan += amount // (again and again and...)
}

//Employee实现SpendSalary方法
func (e *Employee) SpendSalary(amount float32) {
	e.money -= amount // More vodka please!!! Get me through the day!
}

// 定义interface
type Men interface {
	SayHi()
	Sing(lyrics string)
	Guzzle(beerStein string)
}

type YoungChap interface {
	SayHi()
	Sing(song string)
	BorrowMoney(amount float32)
}

type ElderlyGent interface {
	SayHi()
	Sing(song string)
	SpendSalary(amount float32)
}

package main

import "fmt"

type Human struct {
	name string
	age int
	phone string
}

type Student struct {
	Human //匿名字段
	school string
	loan float32
}

type Employee struct {
	Human //匿名字段
	company string
	money float32
}

//Human实现SayHi方法
func (h Human) SayHi() {
	fmt.Printf("Hi, I am %s you can call me on %s\n", h.name, h.phone)
}

//Human实现Sing方法
func (h Human) Sing(lyrics string) {
	fmt.Println("La la la la...", lyrics)
}

//Employee重载Human的SayHi方法
func (e Employee) SayHi() {
	fmt.Printf("Hi, I am %s, I work at %s. Call me on %s\n", e.name,
		e.company, e.phone)
	}

// Interface Men被Human,Student和Employee实现
// 因为这三个类型都实现了这两个方法
type Men interface {
	SayHi()
	Sing(lyrics string)
}

func main() {
	mike := Student{Human{"Mike", 25, "222-222-XXX"}, "MIT", 0.00}
	paul := Student{Human{"Paul", 26, "111-222-XXX"}, "Harvard", 100}
	sam := Employee{Human{"Sam", 36, "444-222-XXX"}, "Golang Inc.", 1000}
	tom := Employee{Human{"Tom", 37, "222-444-XXX"}, "Things Ltd.", 5000}

	//定义Men类型的变量i
	var i Men

	//i能存储Student
	i = mike
	fmt.Println("This is Mike, a Student:")
	i.SayHi()
	i.Sing("November rain")

	//i也能存储Employee
	i = tom
	fmt.Println("This is tom, an Employee:")
	i.SayHi()
	i.Sing("Born to be wild")

	//定义了slice Men
	fmt.Println("Let's use a slice of Men and see what happens")
	x := make([]Men, 3)
	//这三个都是不同类型的元素，但是他们实现了interface同一个接口
	x[0], x[1], x[2] = paul, sam, mike

	for _, value := range x{
		value.SayHi()
	}
}

// 定义a为空接口
var a interface{}
var i int = 5
s := "Hello world"
// a可以存储任意类型的数值
a = i
a = s

type Stringer interface {
	 String() string
}

package main
import (
	"fmt"
	"strconv"
)

type Human struct {
	name string
	age int
	phone string
}

// 通过这个方法 Human 实现了 fmt.Stringer
func (h Human) String() string {
	return "❰"+h.name+" - "+strconv.Itoa(h.age)+" years -  ✆ " +h.phone+"❱"
}

func main() {
	Bob := Human{"Bob", 39, "000-7777-XXX"}
	fmt.Println("This Human is : ", Bob)
}

//实现同样的功能
fmt.Println("The biggest one is", boxes.BiggestsColor().String())
fmt.Println("The biggest one is", boxes.BiggestsColor())

	package main

	import (
		"fmt"
		"strconv"
	)

	type Element interface{}
	type List [] Element

	type Person struct {
		name string
		age int
	}

	//定义了String方法，实现了fmt.Stringer
	func (p Person) String() string {
		return "(name: " + p.name + " - age: "+strconv.Itoa(p.age)+ " years)"
	}

	func main() {
		list := make(List, 3)
		list[0] = 1 // an int
		list[1] = "Hello" // a string
		list[2] = Person{"Dennis", 70}

		for index, element := range list {
			if value, ok := element.(int); ok {
				fmt.Printf("list[%d] is an int and its value is %d\n", index, value)
			} else if value, ok := element.(string); ok {
				fmt.Printf("list[%d] is a string and its value is %s\n", index, value)
			} else if value, ok := element.(Person); ok {
				fmt.Printf("list[%d] is a Person and its value is %s\n", index, value)
			} else {
				fmt.Printf("list[%d] is of a different type\n", index)
			}
		}
	}

	package main

	import (
		"fmt"
		"strconv"
	)

	type Element interface{}
	type List [] Element

	type Person struct {
		name string
		age int
	}

	//打印
	func (p Person) String() string {
		return "(name: " + p.name + " - age: "+strconv.Itoa(p.age)+ " years)"
	}

	func main() {
		list := make(List, 3)
		list[0] = 1 //an int
		list[1] = "Hello" //a string
		list[2] = Person{"Dennis", 70}

		for index, element := range list{
			switch value := element.(type) {
				case int:
					fmt.Printf("list[%d] is an int and its value is %d\n", index, value)
				case string:
					fmt.Printf("list[%d] is a string and its value is %s\n", index, value)
				case Person:
					fmt.Printf("list[%d] is a Person and its value is %s\n", index, value)
				default:
					fmt.Println("list[%d] is of a different type", index)
			}
		}
	}

type Interface interface {
	sort.Interface //嵌入字段sort.Interface
	Push(x interface{}) //a Push method to push elements into the heap
	Pop() interface{} //a Pop elements that pops elements from the heap
}

type Interface interface {
	// Len is the number of elements in the collection.
	Len() int
	// Less returns whether the element with index i should sort
	// before the element with index j.
	Less(i, j int) bool
	// Swap swaps the elements with indexes i and j.
	Swap(i, j int)
}

// io.ReadWriter
type ReadWriter interface {
	Reader
	Writer
}

t := reflect.TypeOf(i)    //得到类型的元数据,通过t我们能获取类型定义里面的所有元素
v := reflect.ValueOf(i)   //得到实际的值，通过v我们获取存储在里面的值，还可以去改变值

tag := t.Elem().Field(0).Tag  //获取定义在struct里面的标签
name := v.Elem().Field(0).String()  //获取存储在第一个字段里面的值

var x float64 = 3.4
v := reflect.ValueOf(x)
fmt.Println("type:", v.Type())
fmt.Println("kind is float64:", v.Kind() == reflect.Float64)
fmt.Println("value:", v.Float())

var x float64 = 3.4
v := reflect.ValueOf(x)
v.SetFloat(7.1)

var x float64 = 3.4
p := reflect.ValueOf(&x)
v := p.Elem()
v.SetFloat(7.1)