All you never wanted to know about Strings in Ruby.

strings.rb

# the simple stuff
string = 'uninterpolated string'
string = "interpolated\nstring"

# if you have all kinds of quotes in your strings, these are available if you must
string = %q{uninterpolated string}
string = %Q{interpolated\nstring}

#heredocs!
string = <<END
heredoc
newlines
are
preserved
END
string = <<-END
heredoc where terminator can have whitespace in front of it
    leading whitespace inside the string itself is preserved though (boo, hiss/cool, yay - depending on the situation).
  END
string = <<terminators_can_be_whatever
Seriously, like anything. So long as its not in the string. 
#{'Also they can all interpolate.' if true}
terminators_can_be_whatever

# use any delimiters! (please don't)
string = %{interpolated\nstring}
string = %(interpolated\nstring)
string = %[interpolated\nstring]
string = %"interpolated\nstring"
string = %'interpolated\nstring' # haha I bet you thought I'd be uninterpolated

# works for all % groups!
string = %q"uninterpolated string" # don't ever do this or I will find you and destroy you

# more fun with interpolation!
tab = "\t"
newline = "\n"
version_string = "ruby version: #{RUBY_VERSION}"
code_string = "put any Ruby code in hash brackets and it'll call .to_s on the result: #{Array.new << 5}" # if to_s returns anything other than a String (even a symbol) - Ruby will will make up its own string
@some_instance_variable = 'some value' # this isn't the fun part, see the next line
interpolate_dat_var = "some var: #@some_instance_variable" # look ma, no brackets

# string merging!
mix_and_match = "interpolate\n"'more like interp-o-LATE \namirite\n?' # damn this is ugly

# single characters too!
string = ?x
string = ?\n # takes all the backslash interpolations
string = ?\u2620 # skull and crossbones! freakin' utf!

# bonus round! arrays of strings
array = %w{create uninterpolated array of strings}
array = %W{create interpolated\narray of strings}

string = <<-'END'
#{this} will NOT be interpolated
END