GoLang 知识点补充（一）

	var (
		aa int     = 10
		bb string  = "zzs"
		cc bool    = false
		dd float32 = 3.14
	)
	fmt.Printf("aa:%d,bb:%s,cc:%t,dd:%f", aa, bb, cc, dd)

• 测试代码

const (
	BEIJING = iota
	SHANGHAI
	TIANJIN
)

const (
	a = 10 * iota
	b
	c
)

const (
	aa, bb = 1 + iota, 2 + iota //iota = 0
	cc, dd                      //iota = 1
	ee, ff = 2 * iota, 3 * iota //iota = 2
	gg, hh
)

func main() {
	fmt.Println(BEIJING)
	fmt.Println(SHANGHAI)
	fmt.Println(TIANJIN)
	fmt.Println("=============")
	fmt.Println(a)
	fmt.Println(b)
	fmt.Println(c)
	fmt.Println("=============")
	fmt.Println(aa)
	fmt.Println(bb)
	fmt.Println(cc)
	fmt.Println(dd)
	fmt.Println(ee)
	fmt.Println(ff)
	fmt.Println(gg)
	fmt.Println(hh)
}

• 运行结果
  

• Import导包路径问题
  

• 测试代码
  切片是引用传递，就算从其它切片中截取出来一段，对其进行改变同时也会改变原始切片
  使用copy函数可以对其进行深拷贝

func main() {
	arr := []int{1, 2, 3, 4, 5}
	arr1 := arr[2:4]
	arr1[0] = 999
	fmt.Println(arr[0])
	fmt.Println(arr1[0])
	fmt.Printf("%pn", arr)
	fmt.Printf("%pn", arr1)

	arr2 := make([]int, len(arr))
	copy(arr2, arr)
	fmt.Println(arr2)
}

type Human struct {
	name string
	sex  bool
}

func (h *Human) Eat() {
	fmt.Println("Eat...")
}

type SuperMain struct {
	Human
	level int
}

func (s *SuperMain) Eat() {
	fmt.Println("superEat...")
}
func (s *SuperMain) Sleep() {
	fmt.Println("superSleep...")
}

func main() {
	s := &SuperMain{
		Human: Human{
			name: "zzs",
			sex:  true,
		},
		level: 10,
	}

	s.Eat()
	s.Sleep()
}

type Animal interface {
	Eat()
	Sleep()
	Play()
}

type Cat struct {
}

func (c *Cat) Eat() {
	fmt.Println("Cat Eat...")
}

func (c *Cat) Sleep() {
	fmt.Println("Cat Sleep...")
}

func (c *Cat) Play() {
	fmt.Println("Cat Play...")
}

type Dog struct {
}

func (d *Dog) Eat() {
	fmt.Println("Dog Eat...")
}

func (d *Dog) Sleep() {
	fmt.Println("Dog Sleep...")
}

func (d *Dog) Play() {
	fmt.Println("Dog Play...")
}

func main() {
	var animal Animal
	animal = &Cat{}
	animal.Eat()
	animal.Sleep()
	animal.Play()
	animal = &Dog{}
	animal.Eat()
	animal.Sleep()
	animal.Play()
	AnimalToDo(&Cat{})
	AnimalToDo(&Dog{})
}

func AnimalToDo(a Animal) {
	a.Eat()
	a.Sleep()
	a.Play()
}

golang中的所有变量都有个pair

type Reader interface {
	ReadBook()
}
type Writer interface {
	WriteBook()
}
type Book struct {
}

func (b *Book) ReadBook() {
	fmt.Println("Read Book ...")
}
func (b *Book) WriteBook() {
	fmt.Println("Write Book ...")
}
func main() {
	// b: pair
	b := &Book{}
	var r Reader
	// r: pair
	r = b
	r.ReadBook()
	var w Writer
	// w: pair
	w = r.(Writer) //此处为什么会断言成功,因为w,r具体的type一致
	w.WriteBook()
}