[Solved] What will be the output of the following Ruby code? class Animal; end class Dog < Animal; end dog = Dog.new puts dog.is_a?(Animal) puts dog.kind_of?(Dog) puts dog.is_a?(String) | Ruby

Ruby - Inheritance

What will be the output of the following Ruby code?

class Animal; end
class Dog < Animal; end

dog = Dog.new
puts dog.is_a?(Animal)
puts dog.kind_of?(Dog)
puts dog.is_a?(String)

Atrue true false

Bfalse true false

Ctrue false true

Dfalse false true

Step-by-Step Solution

Solution:

Step 1: Understand class inheritance
Dog inherits from Animal, so a Dog object is both a Dog and an Animal instance.
Step 2: Evaluate each method call
dog.is_a?(Animal) returns true because Dog is subclass of Animal.
dog.kind_of?(Dog) returns true because dog is instance of Dog.
dog.is_a?(String) returns false because dog is not a String.
Final Answer:
true true false -> Option A
Quick Check:
Inheritance means is_a? true for parent classes [OK]

Quick Trick: Remember inheritance: subclass instances are also parent class instances [OK]

Common Mistakes:

Master "Inheritance" in Ruby

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