list: user.code_common_function code.language: go - # golang builtin functions append length: len make # formatting format print: fmt.Printf format print eff: fmt.Printf format sprint: fmt.Sprintf format es print eff: fmt.Sprintf format print line: fmt.Println # time time hour: time.Hour time minute: time.Minute time second: time.Second time millisecond: time.Millisecond time microsecond: time.Microsecond time nanosecond: time.Nanosecond # IO buf I O: bufio. # strings string convert: strconv. string convert to int: strconv.AtoI