Ruby Language Strings String interpolation
Example
The double-quoted delimiter " and %Q sequence supports string interpolation using #{ruby_expression}:
puts "Now is #{Time.now}"
# Now is Now is 2016-07-21 12:47:45 +0200
puts %Q(Now is #{Time.now})
# Now is Now is 2016-07-21 12:47:45 +0200
