Ruby is awesome

ruby.rb

def ruby_is_great
  # times is an ordinary method that acts just like a loop
  # it takes a block, which is like a lambda/anonymous function
  # except it acts like you would expect a control structure to
  5.times do |i|
    # this will return from ruby_is_great not the block
    return if rand() < 0.5
    puts i
  end
end

# This function takes a block and runs it twice with argument 5
def twice(&block)
  block.call(5)
  block.call(5)
end
# There is a handy form that looks like this
def twice_2
  yield 5
  yield 5
end

# when you use this block, control structures like "break"
# do what they should
twice do |z|
  puts z # will print 5
  break # will stop the block from running any more times
end

class Bob
  # Automatically creates getter and setter methods for you that you can override later
  attr_accessor :lol

  def initialize
    @lol = 4 # handy short form instance variables, no "this."
    4.times do
      @lol += 1 # actually works, no weird "this" tricks like JS
    end
  end
end

b = Bob.new
# setter and getters look exactly like fields when used
puts b.lol
b.lol = 2 

# Ruby has a great immensely powerful standard library and all sorts of handy things
# you don't have to know them or use them when you are learning, but they are great
# when you become pro.

# Finds most common starting letter in English
File.open('/usr/share/dict/words','r').map(&:downcase)
  .chunk(&:ord).map {|c, l| [c.chr, l.length]}
  .max_by(&:last)  # => ["s", 25162]

# I did a presentation on how cool the standard library is: http://thume.ca/2014/06/25/a-tour-of-the-ruby-standard-library/