Ruby中的多行注释？

如何在Ruby中注释多行？

#!/usr/bin/env ruby

=begin
Every body mentioned this way
to have multiline comments.

The =begin and =end must be at the beginning of the line or
it will be a syntax error.
=end

puts "Hello world!"

<<-DOC
Also, you could create a docstring.
which...
DOC

puts "Hello world!"

"..is kinda ugly and creates
a String instance, but I know one guy
with a Smalltalk background, who
does this."

puts "Hello world!"

##
# most
# people
# do
# this


__END__

But all forgot there is another option.
Only at the end of a file, of course.

• 这就是它的外观（通过屏幕截图）-否则很难解释以上注释的外观。点击放大：

=begin
My 
multiline
comment
here
=end

尽管存在=begin和=end，但通常的更正确的注释方法是#在每行上使用。如果您阅读任何ruby库的源代码，您将发现这几乎是在所有情况下进行多行注释的方式。

#!/usr/bin/env ruby

=begin
Between =begin and =end, any number
of lines may be written. All of these
lines are ignored by the Ruby interpreter.
=end

puts "Hello world!"

使用以下任一方法：

=开始
这个
是
一个
评论
块
=结束

要么

＃ 这个
＃是
＃ 一个
＃条评论
＃块

是rdoc当前支持的仅有两个，这是仅使用我认为的这些的一个很好的理由。

=begin
(some code here)
=end

和

# This code
# on multiple lines
# is commented out

都是正确的。第一种类型的注释的优点是可编辑性，因为删除了较少的字符，因此更易于取消注释。第二种类型的注释的优点是可读性-逐行读取代码，很容易分辨出特定的行已被注释掉。您打来的电话，但请考虑谁在追随您，以及他们阅读和维护它们有多容易。

这是一个例子：

=begin 
print "Give me a number:"
number = gets.chomp.to_f

total = number * 10
puts  "The total value is : #{total}"

=end

一切都在你之间发生=begin，并=end不管有多少行代码中包含之间将被视为注释。

注意：请确保=和之间没有空格begin：

• 正确： =begin
• 错误： = begin

=begin comment line 1 comment line 2 =end 确保= begin和= end是该行的第一件事（无空格）

如果有人在Ruby on Rails中寻找在html模板中注释多行的方法，例如= begin = end可能有问题：

<%
=begin
%>
  ... multiple HTML lines to comment out
  <%= image_tag("image.jpg") %>
<%
=end
%>

将因％>关闭image_tag而失败。

在这种情况下，是否将其注释掉也许是有争议的，但是我更喜欢用“ if false”块将不需要的部分括起来：

<% if false %>
  ... multiple HTML lines to comment out
  <%= image_tag("image.jpg") %>
<% end %>

这将起作用。

  def idle
    <<~aid
    This is some description of what idle does.

    It does nothing actually, it's just here to show an example of multiline
    documentation. Thus said, this is something that is more common in the
    python community. That's an important point as it's good to also fit the
    expectation of your community of work. Now, if you agree with your team to
    go with a solution like this one for documenting your own base code, that's
    fine: just discuss about it with them first.

    Depending on your editor configuration, it won't be colored like a comment,
    like those starting with a "#". But as any keyword can be used for wrapping
    an heredoc, it is easy to spot anyway. One could even come with separated
    words for different puposes, so selective extraction for different types of
    documentation generation would be more practical. Depending on your editor,
    you possibly could configure it to use the same syntax highlight used for
    monoline comment when the keyword is one like aid or whatever you like.

    Also note that the squiggly-heredoc, using "~", allow to position
    the closing term with a level of indentation. That avoids to break the visual reading flow, unlike this far too long line.
    aid
  end

请注意，在发布本文时，stackoverflow引擎无法正确呈现语法颜色。作为练习，在您选择的编辑器中测试它的呈现方式。;）