golang中panic，defer，recover简单使用

package main

import (
	"fmt"
)

var(
	h = 11
)

func main() { 
	fmt.Println("start main function.")
	defer func ()  {
		fmt.Println("my defer to func.")
		if err := recover(); err != nil {
			fmt.Println(err)
			return
		}
		fmt.Println("func m")
	}()
	showErr()
	fmt.Println("main m.")
}

func showErr(){
	if h != 10 {
		panic("h not = 10")
	}
	fmt.Println("h ------> ", h)
}