Ruby Language Strings Multiline strings
Example
The easiest way to create a multiline string is to just use multiple lines between quotation marks:
address = "Four score and seven years ago our fathers brought forth on this
continent, a new nation, conceived in Liberty, and dedicated to the
proposition that all men are created equal."
The main problem with that technique is that if the string includes a quotation, it'll break the string syntax. To work around the problem, you can use a heredoc instead:
puts <<-RAVEN
Once upon a midnight dreary, while I pondered, weak and weary,
Over many a quaint and curious volume of forgotten lore—
While I nodded, nearly napping, suddenly there came a tapping,
As of some one gently rapping, rapping at my chamber door.
"'Tis some visitor," I muttered, "tapping at my chamber door—
Only this and nothing more."
RAVEN
Ruby supports shell-style here documents with <<EOT, but the terminating text must start the line. That screws up code indentation, so there's not a lot of reason to use that style. Unfortunately, the string will have indentations depending no how the code itself is indented.
Ruby 2.3 solves the problem by introducing <<~ which strips out excess leading spaces:
2.3
def build_email(address)
return (<<~EMAIL)
TO: #{address}
To Whom It May Concern:
Please stop playing the bagpipes at sunrise!
Regards,
Your neighbor
EMAIL
end
Percent Strings also work to create multiline strings:
%q(
HAMLET Do you see yonder cloud that's almost in shape of a camel?
POLONIUS By the mass, and 'tis like a camel, indeed.
HAMLET Methinks it is like a weasel.
POLONIUS It is backed like a weasel.
HAMLET Or like a whale?
POLONIUS Very like a whale
)
There are a few ways to avoid interpolation and escape sequences:
-
Single quote instead of double quote:
'\n is a carriage return.' -
Lower case
qin a percent string:%q[#{not-a-variable}] -
Single quote the terminal string in a heredoc:
<<-'CODE' puts 'Hello world!' CODE
