Posts tagged with "Heredocs."
  • 2


    Working With Multiline Strings

    I imagine most Rubyists are aware that Ruby has "heredocs," but do you really know all they can do? Let's find out.

    A "here document" is a literal syntax for a multiline String. In the most basic form, they look like this:

    This is a
    as is String!
    # >> "This is a\n  multiline,\nas is String!\n"

    The <<NAME syntax introduces the heredoc, but it actually begins at the start of the following line. It continues until NAME occurs again, at the beginning of a line. Note the trailing newline in the example above. All of the data between start and finish is packaged up into a String and dropped in where the original <<NAME designator appeared.

    There are some important details in that description, namely that the String begins on the next line and that it's inserted where the heredoc was started. This means that the rest of the line where the heredoc is started can have normal Ruby code (though your editor may syntax highlight it badly):

    p <<END_SQL.gsub(/\s+/, " ").strip
    SELECT * FROM     users
             ORDER BY DESC
    # >> "SELECT * FROM users ORDER BY DESC"