你有没有这样的经历:别人审查过你的代码之后给出的注释,你认为是没有必要的?注释代码是为了提高代码的可读性,目的是为了能让其他人更容易理解你的代码。
我特别讨厌这5种注释类型以及制造它们的程序员。希望你不是其中之一。
1.自以为很了不得的程序员
- public class Program
- {
- static void Main(string[] args)
- {
- string message = "Hello World!"; // 07/24/2010 Bob
- Console.WriteLine(message); // 07/24/2010 Bob
- message = "I am so proud of this code!"; // 07/24/2010 Bob
- Console.WriteLine(message); // 07/24/2010 Bob
- }
- }
这个程序员自认为写了一段很了不得的代码,所以觉得有必要用自己的名字对每行代码进行标记。实施版本控制系统(VCS)能实现对代码变更的问责,但是也不会这么明显知道谁应对此负责。
2.过时的程序员
- public class Program
- {
- static void Main(string[] args)
- {
- /* This block of code is no longer needed
- * because we found out that Y2K was a hoax
- * and our systems did not roll over to 1/1/1900 */
- //DateTime today = DateTime.Today;
- //if (today == new DateTime(1900, 1, 1))
- //{
- // today = today.AddYears(100);
- // string message = "The date has been fixed for Y2K.";
- // Console.WriteLine(message);
- //}
- }
- }
如果一段代码已不再使用(即过时),那就删除它——不要浪费时间给这些代码写注释。此外,如果你需要复制这段被删除的代码,别忘了还有版本控制系统,你完全可以从早期的版本中恢复代码。
3.多此一举的程序员
- public class Program
- {
- static void Main(string[] args)
- {
- /* This is a for loop that prints the
- * words "I Rule!" to the console screen
- * 1 million times, each on its own line. It
- * accomplishes this by starting at 0 and
- * incrementing by 1. If the value of the
- * counter equals 1 million the for loop
- * stops executing.*/
- for (int i = 0; i < 1000000; i++)
- {
- Console.WriteLine("I Rule!");
- }
- }
- }
我们都知道基础的编程逻辑是如何工作的——所以你不需要多此一举来解释这些显而易见的工作原理,虽然说你解释得很happy,但这只是在浪费时间和空间。
4.爱讲故事的程序员
- public class Program
- {
- static void Main(string[] args)
- {
- /* I discussed with Jim from Sales over coffee
- * at the Starbucks on main street one day and he
- * told me that Sales Reps receive commission
- * based upon the following structure.
- * Friday: 25%
- * Wednesday: 15%
- * All Other Days: 5%
- * Did I mention that I ordered the Caramel Latte with
- * a double shot of Espresso?
- */
- double price = 5.00;
- double commissionRate;
- double commission;
- if (DateTime.Today.DayOfWeek == DayOfWeek.Friday)
- {
- commissionRate = .25;
- }
- else if (DateTime.Today.DayOfWeek == DayOfWeek.Wednesday)
- {
- commissionRate = .15;
- }
- else
- {
- commissionRate = .05;
- }
- commission = price * commissionRate;
- }
- }
如果你一定要在注释里提及需求,那么不要涉及别人的名字。销售部门的Jim可能会离开公司,而且很有可能大多数程序员根本不知道这是何许人也。不要在注释里提及不相干的事实。
5.“以后再做”的程序员
- public class Program
- {
- static void Main(string[] args)
- {
- //TODO: I need to fix this someday - 07/24/1995 Bob
- /* I know this error message is hard coded and
- * I am relying on a Contains function, but
- * someday I will make this code print a
- * meaningful error message and exit gracefully.
- * I just don't have the time right now.
- */
- string message = "An error has occurred";
- if(message.Contains("error"))
- {
- throw new Exception(message);
- }
- }
- }
这种类型的注释包含了上面所有其他类型。如果是在项目的初始开发阶段,这种待做注释是非常有用的,但如果是在几年后的产品代码——那就会出问题了。如果有什么需要修复的,立马解决,不要把它搁置一边,“以后再做”。
如果你也常常犯这样的注释错误,如果你想了解注释的***做法,我建议你阅读类似于Steve McConnell写的《Code Complete》这样的好书。