Little anagram checker. Had to find out if this tweet was true: https://twitter.com/crampell/status/238620771398864897

anagram.rb

class String
  def anagram?(other)
    letter_count(self) == letter_count(other)  # uses hash equivelence 
  end

  private 
  # "wwaax" =>  { "w" => 2, "a" => 2, "x" => 1 }.. all others 0
  def letter_count(str)
    str.downcase.each_char.inject(Hash.new(0)) { |h, ch| h[ch] += 1; h }
  end

end

unless defined?(assert)
  def assert(cond, msg="Failed assertion")
    raise msg unless cond
  end
end

assert "abc".anagram?("cba")
assert "Abc".anagram?("Cba")
assert !"xxx".anagram?("monkey")

# https://twitter.com/crampell/status/238620771398864897
assert "My Ultimate Ayn Rand Porn".anagram?("Mitt Romney and Paul Ryan")

anagram_192.rb

# 1.9 version courtesy of @bheeshmar

class String
  def anagram?(other)
     raise "Fail!" unless RUBY_VERSION =~ /1.9/
     self.downcase.chars.sort == other.downcase.chars.sort
  end
end

# 1.9.2p290 :008 > "abc".anagram?("cba")
#  => true 
# 1.9.2p290 :009 > "abc".anagram?("xxx")
#  => false 

Sorry Bheesh. Doesn't work in 1.8.7.

>> "abc".sort == "cba".sort
=> false

But, a variant does work in 1.9.

class String
  def anagram?(other)
     raise "Fail!" unless RUBY_VERSION =~ /1.9/
     self.downcase.chars.sort == other.downcase.chars.sort
  end
end

1.9.2p290 :008 > "abc".anagram?("cba")
=> true
1.9.2p290 :009 > "abc".anagram?("xxx")