ruby - - 在 ruby​​ Heredoc 中的 << 之后签名

Question

在下面的内容中，它们都输出相同的内容。我不喜欢在 << 之后添加 - ，就像 <<-END 而不是 <

class Poem


def initialize
    @text = <<END
"Faith" is a fine invention
When Gentlemen can see
But Microscopes are prudent
           In an Emergency.
(Emily Dickinson 1830-1886)
END
  end
  def recite
    puts @text
  end
end

poem = Poem.new
poem.recite

class Poem1
  def initialize
    @text = <<-END
"Faith" is a fine invention
When Gentlemen can see
But Microscopes are prudent
           In an Emergency.
(Emily Dickinson 1830-1886)
    END
  end
  def recite
    puts @text
  end
end

poem1 = Poem1.new
poem1.recite

Answer 1

减号- <<之后字符意味着您可以缩进终止符。

如果这里的文档以 @text = <<END 开头，您必须以 END 终止在该行的开头。但随着@text = <<-END ，可以在 END 前面加空格.

    @text = <<-END
"Faith" is a fine invention
When Gentlemen can see
But Microscopes are prudent
           In an Emergency.
(Emily Dickinson 1830-1886)
    END
#^^^ Here white space