mehdi-farsi

class Hash
  def to_s
    'hash'
  end
end

h = {}

p h.to_s # => "hash"

mehdi-farsi

Symbol.all_symbols.length                      # => 3893
Symbol.all_symbols.grep(/Struct/)              # => [:Struct]

:dummy_symbol
Symbol.all_symbols.length                      # => 3894
Symbol.all_symbols.grep(/dummy_symbol/)        # => [:dummy_symbol]

dummy_variable = nil
Symbol.all_symbols.length                      # => 3895
Symbol.all_symbols.grep(/dummy_variable/)      # => [:dummy_variable]

mehdi-farsi

'pending'.object_id # => 70324176174080
'pending'.object_id # => 70324176168090

mehdi-farsi

:pending.object_id # => 1277788
:pending.object_id # => 1277788

mehdi-farsi

module A
  autoload(:B, './b.rb')
  
  p constants
end

mehdi-farsi

autoload(:C, './c.rb')

module A
  p autoload? :C
end

p autoload? :C

mehdi-farsi

module A
  autoload(:B, './b.rb')

  p autoload?(:B)
  B
  p autoload?(:B)
end

mehdi-farsi

module Engine
  puts 'The Engine module is loading!'
end

mehdi-farsi

module Car
  autoload(:Engine, './engine.rb')

  puts "The Engine module isn't yet loaded!"
  Engine
  puts "The Engine module has been successfully loaded!"
end

mehdi-farsi

class Array
  def my_map
    return self.dup unless block_given?
    
    ary = []
    self.each do |elem|
      ary << yield(elem)
    end
    
    ary