1、接口的定义和实现以及接口的继承

示例：

package mainimport "fmt"//定义接口类型type Humaner interface {	//方法，只有声明，没有实现，由别的类型（自定义类型）实现	sayhi()}type Student struct {	name string	id   int}//Student实现了此方法func (tmp *Student) sayhi() {	fmt.Printf("Student[%s, %d] sayhi\n", tmp.name, tmp.id)}type Teacher struct {	addr  string	group string}//Teacher实现了此方法func (tmp *Teacher) sayhi() {	fmt.Printf("Teacher[%s, %s] sayhi\n", tmp.addr, tmp.group)}type MyStr string//MyStr实现了此方法func (tmp *MyStr) sayhi() {	fmt.Printf("MyStr[%s] sayhi\n", *tmp)}//定义一个普通函数，函数的参数为接口类型//只有一个函数，可以有不同表现，多态func WhoSayHi(i Humaner) {	i.sayhi()}func main() {	s := &Student{"mike", 666}	t := &Teacher{"bj", "go"}	var str MyStr = "hello mike"	//调用同一函数，不同表现，多态，多种形态	WhoSayHi(s)	WhoSayHi(t)	WhoSayHi(&str)	//创建一个切片	x := make([]Humaner, 3)	x[0] = s	x[1] = t	x[2] = &str	//第一个返回下标，第二个返回下标所对应的值	for _, i := range x {		i.sayhi()	}}func main01() {	//定义接口类型的变量	var i Humaner	//只是实现了此接口方法的类型，那么这个类型的变量（接收者类型）就可以给i赋值	s := &Student{"mike", 666}	i = s	i.sayhi()	t := &Teacher{"bj", "go"}	i = t	i.sayhi()	var str MyStr = "hello mike"	i = &str	i.sayhi()}

#执行结果：

Student[mike, 666] sayhiTeacher[bj, go] sayhiMyStr[hello mike] sayhiStudent[mike, 666] sayhiTeacher[bj, go] sayhiMyStr[hello mike] sayhi