How to Determine the type of an object in Ruby?

In this article, we will discuss how to determine the type of an object in Ruby. We can determine the type of an object through different methods ranging from using class method and is_a? method to instance_of? method.

Determining the type of an object using the class method

The class method returns the class of the object.

Syntax:

object.class

Example: In this example, we use the class method to determine the type of object

Ruby

# Determine the type of object using class method

def type_of_object(obj)
  obj.class
end


#Driver code
obj1 = "Hello"
obj2 = 123
obj3 = [1, 2, 3]
obj4 = { key: "value" }

 

# Output the type
puts type_of_object(obj1) # Output: String
puts type_of_object(obj2) # Output: Integer
puts type_of_object(obj3) # Output: Array
puts type_of_object(obj4) # Output: Hash

Output

String
Integer
Array
Hash

Determining the type of an object using is_a? method

The  is_a? method checks if the object is an instance of a specified class or module

Syntax:

object.is_a?(Class)

Example: In this example,we use  the is_a? method to check the type of object .

Ruby

# Determine the type of object using is_a? method


def type_of_object(obj)
  if obj.is_a?(String)
    "String"
  elsif obj.is_a?(Integer)
    "Integer"
  elsif obj.is_a?(Array)
    "Array"
  elsif obj.is_a?(Hash)
    "Hash"
  else
    "Unknown"
  end
end



#Driver code
obj1 = "Hello"
obj2 = 123
obj3 = [1, 2, 3]
obj4 = { key: "value" }

 

# Output the type
puts type_of_object(obj1) # Output: String
puts type_of_object(obj2) # Output: Integer
puts type_of_object(obj3) # Output: Array
puts type_of_object(obj4) # Output: Hash

Output

String
Integer
Array
Hash

Determine the type of an object using instance_of? method

The instance_of? method checks if the object is an instance of a specific class

Syntax:

object.instance_of?(Class)

Example: In this example we use the instance_of? method to check the type of an object in class.

Ruby

# Determine the type of object using instance_of?  method


def type_of_object(obj)
  if obj.instance_of?(String)
    "String"
  elsif obj.instance_of?(Integer)
    "Integer"
  elsif obj.instance_of?(Array)
    "Array"
  elsif obj.instance_of?(Hash)
    "Hash"
  else
    "Unknown"
  end
end
obj1 = "Hello"
obj2 = 123
obj3 = [1, 2, 3]
obj4 = { key: "value" }

puts type_of_object(obj1) # Output: String
puts type_of_object(obj2) # Output: Integer
puts type_of_object(obj3) # Output: Array
puts type_of_object(obj4) # Output: Hash

Output

String
Integer
Array
Hash