Rubyでパーセント記号とリテラル値を使用する例

  # bad (no interpolation needed)
  %(<div class="text">Some text</div>)
  # should be '<div class="text">Some text</div>'

  # bad (no double-quotes)
  %(This is #{quality} style)
  # should be "This is #{quality} style"

  # bad (multiple lines)
  %(<div>\n<span class="big">#{exclamation}</span>\n</div>)
  # should be a heredoc.

  # good (requires interpolation, has quotes, single line)
  %(<tr><td class="name">#{name}</td>)

  # bad
  name = %q(Bruce Wayne)
  time = %q(8 o'clock)
  question = %q("What did you say? ")

  # good
  name = 'Bruce Wayne'
  time = "8 o'clock"
  question = '"What did you say?"'

  # bad
  %r(\s+)

  # still bad
  %r(^/(. *)$)
  # should be /^\/(. *)$/

  # good
  %r(^/blog/2011/(. *)$)

  # bad
  date = %x(date)

  # good
  date = `date`
  echo = %x(echo `date`)

  # bad
  %w[one two three]
  %q{"Test's king!", John said.}

  # good
  %w(one two three)
  %q("Test's king!", John said.)