Dynamically define named classes in Ruby

If you want to create a class with a dynamic name, you’ll have to do almost exactly what you said. However, you do not need to use define_method. You can just pass a block to Class.new in which you initialize the class. This is semantically identical to the contents of class/end.

Remember with const_set, to be conscientious of the receiver (self) in that scope. If you want the class defined globally you will need to call const_set on the TopLevel module (which varies in name and detail by Ruby).

a_new_class = Class.new(Object) do
  attr_accessor :x

  def initialize(x)
    print #{self.class} initialized with #{x}"
    @x = x
  end
end

SomeModule.const_set("ClassName", a_new_class)

c = ClassName.new(10)

...