C# coding style: comments

Most C# style guides recommend against the /* ... */ commenting style, in favor of // or ///. Why is 开发者_Go百科the former style to be avoided?

I wouldn't say I have a strong view against either - but IMO the biggest issue is that /* and */ get messy if you have it nested, with the side effect that you can't copy/paste blocks around safely (quite).

You can too-easily end up with the wrong code commented/enabled, or can end up with it not compiling because you've ended up with a /* /* */ */.

If you copy a block of // around, no harm - just those lines remain commented.

One thing that /* */ can do that // can't is to comment an interior portion of a line. I'll sometimes use this to comment a parameter to a method where something isn't obvious:

        point = ConvertFromLatLon(lat, lon, 0.0 /* height */ ) ;

In this case the constant, 0.0, being passed as the third parameter is representing height. Of course this might be better:

        double height = 0.0;
        point = ConvertFromLatLon(lat, lon, height) ;

(I'm more likely to use the /* */ intra-line temporarily, to just try out passing a specific value.)

There are a few reasons to prefer // to /*.. */.

• As JaredPar mentioned, there are weird comment-nesting issues that can crop up with /* */ usage.
• If you ever write/wrote some code that processes source code files, you'll be really happy if the // method is all that you have to deal with.
• It is far easier to visually detect a large block of commented code with the "//" method, particularly if syntax coloring is unavailable. In fact, you'll often see the individual lines in a /* */ block prefixed with a *, just to be safe.
• The XML commenting style that can be used to produce code documentation requires "///" to be used.

One example that comes to mind is that it's possible to accidentally interrupt a /* style comment. For example

/* This is the start of a comment that documents the 
   behavior of the +-*/ operators in our program
*/ 

This code does not compile, while the // variant would. Also the /// represents a specific style of documentation to which external tools respond differently.

/* */ is fine for multi-line code blocks. For instance at the top of a code file, copyright info etc.

// is easier for single line.

Always use /// for at least all public members in a class as your XML documentation gets generated from that from which you can create help files.

I think you comment as you want since most of us are commenting via shortcuts in Visual Studio. I use ctr+K, ctrl+C all selected rows are comented and ctr+K ctrl+U to uncomment selected rows.

My opinion is that "//" is just easier to type in than /**/

I think /* */ will eventually go the way of the Dodo because in Visual Studio you can just select a block of code and hit CTRL-E,C to comment it out using the // style.

I always use // for actual COMMENTS, while I save the /* */ for code I temporarily do not want to run for debugging/development purposes.

By using only //, then you can be sure you can comment out a large block of lines/methods etc without nesting comments and making your compiler cry.

My guess is because one requires explicit syntax on EACH line and one creates comments that can comment out large sections of code if the closing */ is not used. It's just not as safe.