String [ruby-doc.org] Str % arg → new_str click to toggle source Format—Uses str as a format specification, and returns the result of applying it to arg.
![String [ruby-doc.org]](http://cdn.pearltrees.com/s/pic/th/class-string-ruby-2-1-80968642)
If the format specification contains more than one substitution, then arg must be an Array or Hash containing the values to be substituted. Ruby on Rails Screencasts. Code School - RailsForZombies. Try ruby! (in your browser)