%
%(p1)
public
Format—Uses str as a format specification, and returns the result of applying it to arg. If the format specification contains more than one substitution, then arg must be an Array containing the values to be substituted. See Kernel::sprintf for details of the format string.
"%05d" % 123 #=> "00123" "%-5s: %08x" % [ "ID", self.id ] #=> "ID : 200e14d6"
Use it with HAML
Like Henrik pointed out <a href=“http://henrik.nyh.se/2008/01/surround-helper-alternative-in-haml”>in his blogpost, this method is particulary useful when using HAML (http://haml-lang.com/) in Rails.
Instead of usind the HAML-Helper ‘surround’ (etc) you can just write
= "(%s)" % link_to("Edit", ...)
Or with two Arguments:
= "(%s, %s)" % ["Edit", "Delete"]
Thanks very much, Henrik!