difference between is_a and kind_of ruby

Difference between is_a? and kind_of? in Ruby

In Ruby, the methods is_a? and kind_of? are used to check the class of an object. They are synonyms and can be used interchangeably. However, is_a? is more commonly used in the Ruby community [1].

The is_a? method is used to check if an object is an instance of a specific class or any of its subclasses. It returns true if the object is an instance of the specified class or any of its subclasses, and false otherwise.

The kind_of? method is also used to check if an object is an instance of a specific class or any of its subclasses. It behaves the same way as is_a? and returns true if the object is an instance of the specified class or any of its subclasses, and false otherwise.

Here's an example to illustrate the usage of is_a? and kind_of?:

class Animal
end

class Dog < Animal
end

class Cat < Animal
end

animal = Animal.new
dog = Dog.new
cat = Cat.new

puts animal.is_a?(Animal) # Output: true
puts dog.is_a?(Animal) # Output: true
puts cat.is_a?(Animal) # Output: true

puts animal.kind_of?(Animal) # Output: true
puts dog.kind_of?(Animal) # Output: true
puts cat.kind_of?(Animal) # Output: true

In the example above, the objects animal, dog, and cat are all instances of the Animal class. Therefore, calling is_a?(Animal) or kind_of?(Animal) on any of these objects will return true.

Both is_a? and kind_of? methods can be used to check if an object belongs to a specific class or any of its subclasses. They are useful for type checking and conditional branching in Ruby programs.