test.rb

class Person
  attr_accessor :name
  
  def something
    puts "The current value of the instance variable is:" 
    p @name
  end
end

p = Person.new # Create a new instance of the Person class

p.something
# prints:
#=> The current value of the instance variable is:
#=> nil

p.name = "Mark" # Use the method `name=` to assign something

p.something
# prints:
#=> The current value of the instance variable is:
#=> "Mark"

# Use the method `name` to read the value
puts p.name
# prints:
#=> Mark