// 实现枚举例子

type State int

// iota 初始化后会自动递增
const (
    Running State = iota // value --> 0
    Stopped              // value --> 1
    Rebooting            // value --> 2
    Terminated           // value --> 3
)

func (this State) String() string {
    switch this {
    case Running:
        return "Running"
    case Stopped:
        return "Stopped"
    default:
        return "Unknow"
    }
}

func main() {
    state := Stopped
    fmt.Println("state", state)
}
// 输出 state Running
// 没有重载String函数的情况下则输出 state 0

package main

import "fmt"

func testSliceParams(strs []string, msg string) {
    fmt.Printf("WangAo test: strs----2: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    tmp := strs[0]
    strs[0] = msg
    fmt.Printf("WangAo test: strs----3: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    strs = append(strs, msg)
    fmt.Printf("WangAo test: strs----4: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    strs[0] = tmp
    fmt.Printf("WangAo test: strs----5: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    strs = append(strs, msg)
    fmt.Printf("WangAo test: strs----6: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    strs = append(strs, msg)
    fmt.Printf("WangAo test: strs----7: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    strs = append(strs, msg)
    fmt.Printf("WangAo test: strs----8: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    strs = append(strs, msg)
    fmt.Printf("WangAo test: strs----9: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    tmp = strs[0]
    strs[0] = msg
    fmt.Printf("WangAo test: strs---10: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
}

func main()  {
    strs := make([]string, 0, 3)
    strs = append(strs, "test1")
    fmt.Printf("WangAo test: strs----1: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)
    testSliceParams(strs, "test2")
    fmt.Printf("WangAo test: strs---11: %d %d %p %v\n", len(strs), cap(strs), &strs, strs)

}