go筆記06

package main

import "fmt"

//type hero struct {
// name string
// age int
// power int
//}
//func test (m map[int]hero) {
// stu := m[2]
// stu.power = 80
// m[2] = stu
// fmt.Printf("%p\n",m)
//}
//func test1 (h hero) {
// h.power = 120
// fmt.Println(h)
//}
func main() {
//m := make(map[int]hero)
//m[1] = hero{"zhnag",1,1}
//m[2] = hero{"zhn333ag",1,1}
//h := hero{"ssdsd",1,2}
//fmt.Println(h)
//test1(h)
//fmt.Println(h)
//var i int
//i = 100
//fmt.Printf("%d\n",i)
//fmt.Printf("%p\n",i)
//fmt.Printf("%p\n",&i)
//fmt.Printf("%d\n",*&i)
////指針變量
//var p *int
//p = &i //把變量i地址賦值給變量p
//fmt.Println(p)
//*p = 80
//fmt.Println(*p)
//fmt.Printf("i=%d,p=%p",i,p)
//注意
//1.默認值 nil
//空指針
//var p *int
//fmt.Println(p)
//野指針 指針變量指向了一個未知的空間，會報錯，程序不允許出現野指針
//var p *int
//*p = 45
//fmt.Println(p)
//var a int
//var p *int
//p = &a
//*p = 78
//fmt.Println(p,*p)
//new函數
//var p *int
//p = new(int) //創建一個int類型的 空間
//*p = 57
//fmt.Println(*p)
//自動推導類型
//q := new(int)
//*q = 999
//fmt.Println(q,*q)
//& 取地址 引用
//* 取值 解引用
//a := 10
//b := 20
////普通變量是值傳遞
//swap(a,b)
//fmt.Println(a,b)
//swap1(&a,&b)
//fmt.Println(a,b)
//數組
//arr := [3]int{1,2,3}
////數組指針
//var p *[3]int
////指針和數組建立關係
//p = &arr
//fmt.Println(p,*p)
////通過指針操作數組
//(*p)[0] = 123
////*p[0] = 123
//p[1] = 345
//fmt.Println(p,*p)
//arr := [5]int{1,2,3,4,5}
//p1 := &arr
//p2 := &arr[0]
//fmt.Printf("%p\n",p1)
//fmt.Printf("%p\n",p2)
//fmt.Printf("%T\n",p1)
//fmt.Printf("%T\n",p2)
//a := [5]int{1,2,3,4,5}
//swap(&a)
//fmt.Println(a)
//a := 10
//b := 20
//c := 30
////指針數組
//var arr = [3]*int{&a,&b,&c}
//a := [3]int{1,2,3}
//var arr = [1]*[3]int{&a}
//fmt.Println(arr)
//fmt.Printf("%T\n",arr)
//(*arr[0])[0] = 345
//fmt.Println(a)
//切片和指針
//s := [5]int{1,2,3,4,5}
//p := &s
//fmt.Printf("%p\n",p)
//fmt.Printf("%p\n",s)
//
//(*p)[1] = 345
////*p[1] = 345
//fmt.Println(p)
//a := 10
////一級指針
//p := &a
//fmt.Println(p)
//fmt.Printf("%T\n",p)
////二級指針
//p2 := &p
//fmt.Printf("%T\n",p2)
//順序初始化
//var s1 = Student{Person{
// 1,
// "zhang",
// 1},
// 1}
//fmt.Println(s1)
//s2 := Student{Person{1,"22",2},"11",2}
////fmt.Println(s2)
////s3 := Student{score:100}
////fmt.Println(s3)
//s2.score = 90
//s2.Person.id = 100
//s2.Person = Person{1,"22",4}
//fmt.Println(s2)
//s2.name = "sdfsfdsdfsf"
//fmt.Println(s2)
//指針類型匿名字段
//var s Student1
//s.score = 100
//s.Person = new(Person)
//s.id = 19
//fmt.Println(s.name,s,s.Person)
//var c Cat
//c.name = "小花"
//c.show()
//var d Dog
//d.name = "小黑"
//d.show()
//stu := Student{"zhang",1,1}
//
//fmt.Println(stu)
//stu1 :=Student{"li",3,3}
//stu.print()
//fmt.Println(stu1)
//p := person10{1,"make",22}
//p.PrintInfo1()
//p.PrintInfo2()
//fmt.Println(p.PrintInfo1)
//fmt.Println(p.PrintInfo2)
//fmt.Printf("%T\n",p.PrintInfo1)
//fmt.Printf("%T\n",p.PrintInfo2)
//方法值，隱式傳遞
//pfunc1 := p.PrintInfo1
//pfunc1()
////方法表達式
//pfunc2 := person10.PrintInfo1
//pfunc2(p)
//pfunc3 := (*person10).PrintInfo2
//pfunc3(&p)
//fmt.Printf("%T\n",pfunc2)
//fmt.Printf("%T\n",pfunc3)
//var h Humaner
//stu := student11{"xiaoming",1}
////stu.sayHi()
////將對象信息賦值給接口類型變量
//h = &stu
//h.sayHi()
//var i interface{}
//fmt.Println(i)
//fmt.Printf("%T\n",i)
//var i []interface{}
//fmt.Printf("%T\n",i)
//i = append(i,10,2.2,'a')
//fmt.Println(i)
//var i interface{}
//i = 10.2
////value, ok := element.(T)
////值， 值得判斷 := 接口變量.(數據類型)
//value, ok := i.(int)
//if ok {
// fmt.Println("int",value)
//} else {
// fmt.Println("not int")
//}
//result, err := test(10,10)
//if err != nil {
// fmt.Println("err= ", err)
//} else {
// fmt.Println(result)
//}
//fmt.Println("hello")
//fmt.Println("hello")
//fmt.Println("hello")
//fmt.Println("hello")
//panic("hello error")
//fmt.Println("hello")
//fmt.Println("hello")
//fmt.Println("hello")
//fmt.Println("hello")
//defer fmt.Println("hello")
//defer fmt.Println("hello1")
//defer fmt.Println("hello2")
//panic("sdsfdsd")
//defer fmt.Println("hello3")
//defer fmt.Println("hello4")
//defer fmt.Println("hello5")
//fmt.Println("wnag")
testA()
testB()
testC()
}
func testA() {
fmt.Println("testA")
}
func testB() {
defer func() {
recover()
}()
panic("error")
panic("error")
fmt.Println("testB")
}
func testC() {
fmt.Println("testC")
}
func test(a, b int) (result int, err error) {
err = nil
if b == 0 {
fmt.Println("err=", err)
} else {
result = a / b
}
return
}
//定義接口 一般以er爲結尾，根據接口實現功能
type Humaner interface {
//方法
sayHi()
}
type student11 struct {
name string
age int
}
func (s *student11)sayHi() {
fmt.Printf("hi %s",s.name)
}
type person10 struct {
id int
name string
age int
}
func (p person10) PrintInfo1() {
fmt.Printf("%p,%v\n",&p,p)
}
func (p *person10) PrintInfo2() {
fmt.Printf("%p,%v\n",p,*p)
}

//type Student struct {
// name string
// age int
// score int
//}
////普通類型屬性改動不影響 指針類型會影響
//func (s *Student)print() {
// s.score = -9
// fmt.Println(*s)
//}
//type Cat struct {
// name string
// age int
//}
//type Dog struct {
// name string
// age int
//}
//func (c Cat)show() {
// fmt.Printf("%s 喵喵喵\n",c.name)
//}
//func (d Dog)show() {
// fmt.Printf("%v %v\n",d.name,"汪汪汪")
//}
//方法定義
//func (對象)方法 (參數列表) 返回值列表 {
// 代碼體
//}
////父類
/*type Person struct {
id int
name string
age int
}
//子類
type Student struct {
Person
name string
score int
}
type Student1 struct {
*Person
score int
}*/
//func swap(p *[5]int) {
// p[0] = 123
//}
//func swap1(num1, num2 *int) {
// *num1, *num2 = *num2, *num1
// fmt.Println(*num1, *num2)
//}
//func swap(num1, num2 int) {
// num1, num2 = num2, num1
// fmt.Println(num1, num2)
//}