test_kind.rb

2.2.0 :001 > class A
2.2.0 :002?>   end
 => nil 
2.2.0 :003 > class B < A
2.2.0 :004?>   end
 => nil 
2.2.0 :005 > a = A.new
 => #<A:0x0000000155df60> 
2.2.0 :006 > b = B.new
 => #<B:0x00000001542670> 
2.2.0 :007 > a.is_a? A
 => true 
2.2.0 :008 > a.is_a? B
 => false 
2.2.0 :009 > b.is_a? A
 => true 
2.2.0 :010 > 
2.2.0 :011 > b.is_a? B
 => true 
2.2.0 :012 > b.instance_of? B
 => true 
2.2.0 :013 > b.instance_of? A
 => false