Accessing InstanceClass Variables in Singleton Classes

Singleton classes share their instance/class variables with their object.

class Example
  @@foo = :example
end

def Example.foo
  class_variable_get :@@foo
end

Example.foo #=> :example

—``` class Example def initialize @foo = 1 end

def foo @foo end end

e = Example.new

e.instance_eval <<-BLOCK def self.increase_foo @foo += 1 end BLOCK

e.increase_foo e.foo #=> 2

---

Blocks close around their instance/class variables target. Accessing instance or class variables using a block in `class_eval` or `instance_eval` isn’t possible. Passing a string to `class_eval` or using `class_variable_get` works around the problem.

class Foo @@foo = :foo end

class Example @@foo = :example

Foo.define_singleton_method :foo do @@foo end end

Foo.foo #=> :example ```