error
var write = errors.New("分母不能为0")/*
通用处理方式
*/
func run(a int)(int,error) {if a == 0 {return 0,write}return 66 / a, nil
}func main() {v, error := run(0)if error != nil {fmt.Println(v,error)return}fmt.Println(v)
}
flag
/*相当于设置的默认值*/
var Input_Name = flag.String("name", "dabaojian", "input your name")
var Input_Age = flag.Int("age", 20, "input your age")
var Input_Gender = flag.String("gender", "male", "input your age")
var Input_flagvar intfunc Init2() {flag.IntVar(&Input_flagvar, "flagname", 1234, "help message for flagname")
}/**
go build flag.go 编译：
./flag -name=world 运行：
下面就能获取到运行时设置的参数，如果没设置，就是用默认值*/
func main() {Init2()flag.Parse() //通过启动参数 获取flag的值////fmt.Printf("args=%s, num=%d\n", flag.Args(), flag.NArg())//fmt.Printf("flag num=%d\n", flag.NFlag())////for i := 0; i != flag.NArg(); i++ {// fmt.Printf("arg[%d]=%s\n", i, flag.Arg(i))//}fmt.Println("name=", *Input_Name)fmt.Println("age=", *Input_Age)fmt.Println("gender=", *Input_Gender)fmt.Println("flagname=", Input_flagvar)
}