是否可以在R中有多行注释？ [英] Is it possible to have a multi-line comments in R?

问题描述

我发现这个旧主题<​​/a>（来自一年多以前），这解释了R如何不支持多行注释（例如/ PHP的/ *注释* /）。

I found this old thread (from over a year ago), which explains how come R doesn't support a multi-line comments (like /* comment */ of PHP, for example).

我想知道这是否已在过去一年中解决，或者如果有其他替代品？ （例如，在notepad ++和npptor中，你可以标记一行，并按ctrl + q将它们标记为注释，是否有其他IDE类似的解决方案？）

I am wondering if this has been resolved in the past year, or if there are other alternatives? (For example, in notepad++ with npptor, you can mark a bunch of lines and press ctrl+q to mark them all as comments, are there similar solutions for other IDE's ?)

推荐答案

如果你愿意，你可以使用独立的字符串多行注释—我一直认为比 if（FALSE）{} 更漂亮。该字符串将被评估，然后被丢弃，因此只要它不是一个函数的最后一行，就不会发生任何事情。

You can, if you want, use standalone strings for multi-line comments — I've always thought that prettier than if (FALSE) { } blocks. The string will get evaluated and then discarded, so as long as it's not the last line in a function nothing will happen.

"This function takes a value x, and does things and returns things that
 take several lines to explain"
doEverythingOften <- function(x) {
     # Non! Comment it out! We'll just do it once for now.
     "if (x %in% 1:9) {
          doTenEverythings()
     }"
     doEverythingOnce()
     ...
     return(list(
         everythingDone = TRUE, 
         howOftenDone = 1
     ))
}

b $ b

主要的限制是，当你注释的东西，你必须看你的引号：如果你有一种内部，你必须使用另一种类的评论;如果你有一些东西像字符串与'postrophes在块内，那么没有办法这种方法是一个好主意。但是仍然有 if（FALSE）阻塞。

两种方法都有的另一个限制是，只能在表达式在语法上有效的地方使用这样的块 - 没有注释掉部分列表，

The other limitation, one that both methods have, is that you can only use such blocks in places where an expression would be syntactically valid - no commenting out parts of lists, say.

关于在IDE中做什么：我是Vim用户，我找到
NERD评论员一个完美的工具，快速评论或取消注释多行。

Regarding what do in which IDE: I'm a Vim user, and I find NERD Commenter an utterly excellent tool for quickly commenting or uncommenting multiple lines. Very user-friendly, very well-documented.

最后，在R提示符下（至少在Linux下），有一个可爱的 Alt Shift - ＃可注释当前行。非常高兴把一条线搁置，如果你正在一个单线，然后意识到你需要一个准备步骤先。

Lastly, at the R prompt (at least under Linux), there's the lovely Alt-Shift-# to comment the current line. Very nice to put a line 'on hold', if you're working on a one-liner and then realise you need a prep step first.

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