一、Interfaces and Inheritance and Conversion

package main

import "fmt"

type Humaner interface {
    
	SayHello()
}
type Personer interface {
    
	Humaner
	Say()
}
type Student struct {
    
}

func (s *Student) SayHello() {
    
	fmt.Println("大家好")
}
func (s *Student) Say() {
    
	fmt.Println("你好")
}
func main() {
    
	var stu Student
	var per Personer
	per = &stu
	per.Say()
	per.SayHello() // 可以调用所继承的接口中的方法.

	var h Humaner
	h = per
	// per=h
	h.SayHello()
}

继承就是子类继承父类的特征和行为,使得子类对象（实例）具有父类的实例域和方法,或子类从父类继承方法,使得子类具有父类相同的行为.

Interface inheritance is a concept from design patterns.接口继承,subtyping.Describes when an object can be used in place of another object.接口是一个抽象类型,是抽象方法的集合,接口通常以interface来声明.Interfaces can inherit multiple interfaces because interfaces only define behavior and do not contain the meaning of categories and do not refer to a specific kind of thing,

二、空接口

空接口(interface{})不包含任何的方法,正因为如此,所有的类型都实现了空接口,因此空接口可以存储任意类型的数值.

package main

import "fmt"

func main() {
    
	var i interface{
    }
	i = 123
	i = "abc"
	fmt.Println(i)
	var s []interface{
    }
	s = append(s, 123, "abc", 12.3)
	for j := 0; j < len(s); j++ {
    
		fmt.Println(s[j])
	}
}