>> a = 1..10
=> 1..10
>> a.class
=> Range
>> a.to_a
=> 
>> b = 1...10
=> 1....10
>> b.to_a
=> 
>> b.include? 10
=> 
>> b.include? 8
=> 
>> b.step(2) {|x| print "#{x} " }
>> 1..3.to_a
>> r = 0...100 => 0....100 >> r.member? 50 => >> r.include? 99.9 => >> r.member? 99.9 =>
>> true.class => >> false.class => >> puts "hello" if 0 >> puts "hello" if nil >> puts "hello" if "" >>
>> x = :sym => :sym >> x.class => >> x == 'sym' => >> x == :sym => >> z = :'a long symbol' => :"a long symbol" >> z.class => >> x == 'sym'.to_sym => >> x.to_s == 'sym' =>