ruby21.md

   1 ---
   2 title: Ruby 2.1
   3 category: Ruby
   4 layout: 2017/sheet
   5 tags: [Archived]
   6 intro: |
   7   Quick reference to the [new features in Ruby 2.1](https://www.ruby-lang.org/).
   8 ---
   9
  10 ### Named arguments with defaults
  11
  12 ```ruby
  13 # length is required
  14 def pad(num, length:, char: "0")
  15   num.to_s.rjust(length, char)
  16 end
  17 ```
  18
  19 ```ruby
  20 pad(42, length: 6) #=> "000042"
  21 pad(42) #=> #<ArgumentError: missing keyword: length>
  22 ```
  23
  24 ### Module.prepend
  25
  26 ```ruby
  27 prepend(
  28   Module.new do
  29     define_method ...
  30   end
  31 )
  32 ```
  33
  34 ### References
  35
  36 - http://globaldev.co.uk/2013/03/ruby-2-0-0-in-detail
  37 - http://globaldev.co.uk/2014/05/ruby-2-1-in-detail