=begin
My 
multiline
comment
here
=end

#!/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.

这就是它的样子（通过截图）——否则很难解释上面的评论会是什么样子。单击以放大：

#!/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!"

=begin
(some code here)
=end

and

# This code
# on multiple lines
# is commented out

都是正确的。第一种注释类型的优点是可编辑性，因为删除的字符更少，所以取消注释更容易。第二类注释的优点是逐行读取代码的可读性，更容易判断某一行已被注释掉。你的电话，但想想谁会来找你，他们阅读和维护起来有多容易。

使用以下任一项：

=begin
This
is
a
comment
block
=end

or

# This
# is
# a
# comment
# block

是rdoc目前唯一支持的两个，我认为这是一个很好的理由只使用这些。

尽管存在=begin和=end，但正常且更正确的注释方式是在每行上使用#。如果您阅读任何ruby库的源代码，您会发现几乎在所有情况下都是这样进行多行注释的。