instance_variable_inspection

🛠️ Inspect and Manipulate Instance Variables

Use instance_variables, instance_variable_get, and instance_variable_set to inspect or modify an object’s state without exposing accessors. This is handy for serializers, object cloners, or debugging tools. Remember that altering internals can break invariants—use with care.

class Session
  def initialize(user_id)
    @user_id = user_id
    @data = {}
  end
end

session = Session.new(42)
# List current instance variables
session.instance_variables  #=> [:@user_id, :@data]

# Read and modify them dynamically
uid = session.instance_variable_get(:@user_id)  #=> 42
session.instance_variable_set(:@data, { cart: [1,2,3] })