How to get the Class of an Object in Ruby

Greetings, friends! As you may know, the Ruby programming language is a pure object-oriented language. Practically everything in Ruby is an object. This means we can use the Object#class method to get the name of any object's class.

puts 0.class # Integer
puts 3.14.class # Float
puts "".class # String
puts false.class # FalseClass
puts true.class # TrueClass
puts nil.class # NilClass
puts [].class # Array

hash = {foo: 0, bar: 1, baz: 2}
puts hash.class # Hash

class FancyClass
  def saySomethingFancy
    puts "How Quaint"
  end
end

fancyPerson = FancyClass.new
puts fancyPerson.class # FancyClass

Getting the class name of an object is useful for learning the internals of Ruby or a Ruby library. You can also use the Object#class method to help you debug Ruby code. Sometimes, you may need to figure out where a variable's class is defined or what class it belongs to.

Resources

• run.rb
• Object#class