Notation %

There is also a Perl-inspired way to quote strings: by using % (percent character) and specifying a delimiting character, for example:

%{78% of statistics are "made up" on the spot}
=> "78% of statistics are \"made up\" on the spot"

Any single non-alpha-numeric character can be used as the delimiter, %[including these], %?or these?, %~or even these things~. By using this notation, the usual string delimiters “ and ‘ can appear in the string unescaped, but of course the new delimiter you’ve chosen does need to be escaped. However, if you use %(parentheses), %[square brackets], %{curly brackets} or % as delimiters then those same delimiters can appear unescaped in the string as long as they are in balanced pairs:

%(string (syntax) is pretty flexible)
=> "string (syntax) is pretty flexible"

A modifier character can appear after the %, as in %q[], %Q[], %x[] - these determine how the string is interpolated and what type of object is produced:

Here are some more examples:

%Q{one\ntwo\n#{ 1 + 2 }}
=> "one\ntwo\n3"

%q{one\ntwo\n#{ 1 + 2 }}
=> "one\\ntwo\\n#{ 1 + 2 }"

%r/#{name}/i
=> /nemo/i

%w{one two three}
=> ["one", "two", "three"]

%i{one two three} # after Ruby 2.0
=> [:one, :two, :three]

%x{ruby --copyright}
=> "ruby - Copyright (C) 1993-2009 Yukihiro Matsumoto\n"

“Here document” notation

There is yet another way to make a string, known as a ‘here document’, where the delimiter itself can be any string:

string = <<END
on the one ton temple bell
a moon-moth, folded into sleep,
sits still.
END

The syntax begins with « and is followed immediately by the delimiter. To end the string, the delimiter appears alone on a line.

There is a slightly nicer way to write a here document which allows the ending delimiter to be indented by whitespace:

string = <<-FIN
       on the one-ton temple bell
       a moon-moth, folded into sleep
       sits still.

       --Taniguchi Buson, 18th century; translated by X. J. Kennedy
     FIN

To use non-alpha-numeric characters in the delimiter, it can be quoted:

string = <<-"."
       Orchid - breathing
       incense into
       butterfly's wings.

       --Matsuo Basho; translated by Lucien Stryk
     .

Here documents are interpolated, unless you use single quotes around the delimiter.

The rest of the line after the opening delimiter is not interpreted as part of the string, which means you can do this:

strings = [<<END, "short", "strings"]
	a long string
END

=> ["a long string\n", "short", "strings"]

You can even “stack” multiple here documents:

string = [<<ONE, <<TWO, <<THREE]
the first thing
ONE
the second thing
TWO
and the third thing
THREE

=> ["the first thing\n", "the second thing\n", "and the third thing\n"]