Enhance the feedback form in your project to enable users to choose one or more options from a list of at least five options. Include code that adds user selections to either an array or an object and ensure that if a user deselects one of the options, it is removed from the array or object. Add code to convert the array or object to a string.

Add object$-$oriented programming techniques to your project by creating custom objects to manage some of the tasks in your project. Store the objects in a separate file. Create a constructor function for a class of objects and then add methods to your object class prototypes. Create instances of each object class in your code. Your objects and object classes should be designed in such a way that they can be used with other applications.