你是否曾在检查代码时碰到一条在你看来多余的注释？在代码中使用注释的目的是提升代码的可读性，以让那些非原始代码开发者能更好地理解它们。
我甄别出5类让我不胜其扰的注释及5类生成它们的程序员。我希望读过本篇之后，你不会与他们一样坠入同一条河流。作为一项挑战，你不妨把写这5类注释的程序员与5类程序员[英文]作一下匹配。
1. 骄傲型程序员
01 |
public class Program
|
02 |
{ |
03 |
static void Main(string[] args)
|
04 |
{
|
05 |
string message = "Hello World!"; // 07/24/2010 Bob
|
06 |
Console.WriteLine(message); // 07/24/2010 Bob
|
07 |
message = "I am so proud of this code!"; // 07/24/2010 Bob
|
08 |
Console.WriteLine(message); // 07/24/2010 Bob
|
09 |
}
|
10 |
} |
这类程序员对其代码自视甚高，以至于他觉得有必要在每行代码后都要签上自己的大名。应用版本控制系统（VCS）是能知道谁修改了代码，但是乍看之下责任人也不会如此打眼。
2. 过时型程序员
01 |
public class Program
|
02 |
{ |
03 |
static void Main(string[] args)
|
04 |
{
|
05 |
/* This block of code is no longer needed
|
06 |
* because we found out that Y2K was a hoax
|
07 |
* and our systems did not roll over to 1/1/1900 */
|
08 |
//DateTime today = DateTime.Today;
|
09 |
//if (today == new DateTime(1900 1 1))
|
10 |
//{
|
11 |
// today = today.AddYears(100);
|
12 |
// string message = "The date has been fixed for Y2K.";
|
13 |
// Console.WriteLine(message);
|
14 |
//}
|
15 |
}
|
16 |
} |
如果一段代码不再使用了（也就是过时了），请删除它——勿要让你的工作代码被数行冗余的注释弄得七零八乱。而且，你任何时候需要复制这段删除的代码，都可以使用版本控制系统，这样你便能从以前版本中恢复出它来。
3. 显然型程序员
01 |
public class Program
|
02 |
{ |
03 |
static void Main(string[] args)
|
04 |
{
|
05 |
/* This is a for loop that prints the
|
06 |
* words "I Rule!" to the console screen
|
07 |
* 1 million times each on its own line. It
|
08 |
* accomplishes this by starting at 0 and
|
09 |
* incrementing by 1. If the value of the
|
10 |
* counter equals 1 million the for loop
|
11 |
* stops executing.*/
|
12 |
for (int i = 0; i < 1000000; i++)
|
13 |
{
|
14 |
Console.WriteLine("I Rule!");
|
15 |
}
|
16 |
}
|
17 |
} |
我们都知道编程的基本工作逻辑——这可不是什么“编程入门”！你无需浪费时间解释显而易见的程序工作原理，虽然我们很高兴看到你愿意解释代码的功能——但这不过是画蛇添足。
4. 传记型程序员
01 |
public class Program
|
02 |
{ |
03 |
static void Main(string[] args)
|
04 |
{
|
05 |
/* I discussed with Jim from Sales over coffee
|
06 |
* at the Starbucks on main street one day and he
|
07 |
* told me that Sales Reps receive commission
|
08 |
* based upon the following structure.
|
09 |
* Friday: 25%
|
10 |
* Wednesday: 15%
|
11 |
* All Other Days: 5%
|
12 |
* Did I mention that I ordered the Caramel Latte with
|
13 |
* a double shot of Espresso?
|
14 |
*/
|
15 |
double price = 5.00;
|
16 |
double commissionRate;
|
17 |
double commission;
|
18 |
if (DateTime.Today.DayOfWeek == DayOfWeek.Friday)
|
19 |
{
|
20 |
commissionRate = .25;
|
21 |
}
|
22 |
else if (DateTime.Today.DayOfWeek == DayOfWeek.Wednesday)
|
23 |
{
|
24 |
commissionRate = .15;
|
25 |
}
|
26 |
else
|
27 |
{
|
28 |
commissionRate = .05;
|
29 |
}
|
30 |
commission = price * commissionRate;
|
31 |
}
|
32 |
} |
如果你非得在代码中提到某些必需的东西，也别提到人名。Jim from Sales（译注：销售人员Jim）也许离开这家公司了，那些阅读代码的程序员极可能根本就不知道他是谁，更甭提注释里那些毫无干系的事情。
5. “总有一天”型程序员
01 |
public class Program
|
02 |
{ |
03 |
static void Main(string[] args)
|
04 |
{
|
05 |
//TODO: I need to fix this someday – 07/24/1995 Bob
|
06 |
/* I know this error message is hard coded and
|
07 |
* I am relying on a Contains function but
|
08 |
* someday I will make this code print a
|
09 |
* meaningful error message and exit gracefully.
|
10 |
* I just don’t have the time right now.
|
11 |
*/
|
12 |
string message = "An error has occurred";
|
13 |
if(message.Contains("error"))
|
14 |
{
|
15 |
throw new Exception(message);
|
16 |
}
|
17 |
}
|
18 |
} |
这类注释在某种程度上说是前面几种类型的大杂烩。TODO注释在项目初始开发阶段用处不小，但是如果几年后出现在产品代码中——那就会带来麻烦。如果有什么需要修补的，趁现在动手，而不要推迟到以后去做。
如果你不幸是生成这些类型注释的人，或者你想学习注释用法的最佳实践，我推荐你阅读Steve McConnell写的Code Complete（《代码大全》）。这是一本我建议程序员必读的书籍，OSC地址 http://my.oschina.net/justjavac/blog/66624。
你是否在自己的代码中看到了其它类型多余或扰人的注释？请不吝分享。
转自：http://www.oschina.net/question/253614_79956