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.