Use of %() for Strings

I notice a lot of code throughout Rails uses this approach to build up
a String:

a = %(This is line one)
a << %(This is line two)
a

After looking through two books I can't seem to find a description of
what exactly %() does. Can anyone tell me what the benefits of using
%() is?

Thanks,
Dave

The main advantage of %() is it ignores balanced parentheses inside the string. That makes it handy for quoting code.

Like:

code = %( foo(bar(3)) )

using %{} or %() also saves you from escaping embedded quotes in a
string, such as:

    ActiveRecord::Base.connection.execute(%{select id,admin_comments
into outfile "#{file_name}.txt" fields terminated by "," enclosed by
"""" from users where admin_comments!="";})