Ruby & Rails Quiz Answers

def method1
  yield
end

a = <<'"}{|_(_&^+$^)$_$345_$#%$^%^+'
visit ukod.me
"}{|_(_&^+$^)$_$345_$#%$^%^+

class MyClass
  def self.to_s
    "MyClass is cool"
  end

nil.to_a   # => []
Array(nil) # => []

nil.to_h  # => {}

class Example; end

example = Example.new

x = nil
y = "Ruby"

x || y && "Rails" # => ???

require 'set'

tags = SortedSet.new

class Hi
  def initialize(name)
    @name = name
  end

require 'net/http'

[Net::HTTP, Net::HTTP.class] # => [Net::HTTP, Class]

"Euruko".upcase!.chars # => ["E", "U", "R", "U", "K", "O"]

"EURUKO".upcase!.chars # => ???

a = "outer"
1.times do
  a = "inner"
end

h = { a: 1, b: 2 }
h.replace(h.invert)

h[:a] # => ???

numbers = [1, 2, 3]
numbers[1, 0] = [4]

numbers.join("x") # => ???

hash = {a: 1}
hash[:b] = hash

hash[:b][:b][:b][:a] # => ???

a   = [1, 2]
res = []

case a.size

str = "hello\n"
str.chomp!.reverse # => "olleh"

str = "hello"

array = [1, [2]]
array[1] << array

array.flatten # => ???

(1..10).each { |n| break n if n == 5 } # => ???

i = 42

for i in (1...10)
  puts i

def procs_return
  -> { return :lambda }.call

  proc { return :proc }.call

h = Hash.new { [] }

h[:a] << 42
h[:b] << 84

h = Hash.new([])

h[:a] << 42

a = [21, 42, 84]

a[1.2] # => ???

h = {}.compare_by_identity

h["key"] = 42
h["key"] = 84

var = !(!!!())

var # => ???

toggler = %w(start stop).cycle

toggler.next
toggler.next

12345.digits # => ???

a = [1, 2, nil, 2, "", false, 3]

a.select(&:itself) # => ???

class Person
  def firstname = "Jon"
  def lastname = "Jones"

1.0.eql?(1)   # => false
1.0.equal?(1) # => false

1.0 == 1      # => ???

h = { a: 21, b: 42 }.freeze

[*h] # => ???

"aaoo".gsub("a") {|c| c.upcase} # => "AAoo"

"aaoo".gsub("a", "o") {|c| c.upcase} # => ???

words = [["abc", ["def"]], "ghi"]

words[0][0][0][1] # => ???

[1, 3, 2, 1, 2] | [] # => ???

class Device
  def description
    'I\'m a device'
  end

(42 + 0.42).!@.!@ # => ???

["a", *["b", "c"], "d"] * ?: # => ???

def sum
  n = 0

  n += yield

class Greeting
  def self.hello = "hello" if false
end

dec = ->(n) {n-1}
inc = ->(n) {n+1}
dbl = ->(n) {n*2}

def my_method(a)
  a += [4]
end

a = []
upcase   = ->(c) { a << c; c.upcase }
downcase = ->(c) { a << c; c.downcase }

str = "abc".freeze

str += "def"