kmdsbng

class A
  CONST_A = 1
  @@a = 1
  @b = 1

  def self.get_a
    @@a
  end

  def self.get_b

kmdsbng

a = true
b = true

if a && b
  puts "hoge"
end

if a and b
  puts "moge"
end

kmdsbng

a = 1.tap {|i| puts i + i}
a # => 1

b = 1.tap {|i| break i + i}
b # => 2

# >> 2

kmdsbng

# -*- encoding: utf-8 -*-

a = 1 + 3
b = 5 + 4
c = a + b # => 13
d = c + b # => 22

kmdsbng

require 'active_support/all'

class A
  cattr_accessor :hoge
  class << self
    attr_accessor :moge
  end
end

class B < A; end

kmdsbng

require 'rmaybe'

# This code returns "C"
"a b c".split[2].upcase # => "C"

# And if you use maybe. ... .end chain, you can get same result.
"a b c".maybe.split[2].upcase.end # => "C"

# This code causes NoMethodError.
"a b c".split[3].upcase

kmdsbng

def fib_iter(prev2, prev, remain)
  current = prev2 + prev
  remain > 0 ? fib_iter(prev, current, remain - 1) : current
end

# n == 0 => 0, n == 1 => 1, n == 2 => 1, n == 3 => 2, n == 4 => 3, n == 5 => 5 ...
def fib(n)
  return n if [0, 1].include?(n)
  return fib_iter(0, 1, n - 2)
end

kmdsbng

# -*- encoding: utf-8 -*-


old_csv = <<CSV
1,aaa
2,bbb
3,ccc
4,ddd
CSV

kmdsbng

# -*- encoding: utf-8 -*-

require 'yaml'
YAML::ENGINE.yamler= 'syck'
require 'active_support/all'
require 'json'

json = '{"a":"\\u0000"}'

kmdsbng

# -*- encoding: utf-8 -*-

require 'yaml'
YAML::ENGINE.yamler= 'syck'
require 'active_support/all'
require 'json'

json = '{"a":"\\u0000"}'