why reference parameters cannot be optional parameters?

Hi.

 

Ref - The ref keyword is used to pass an argument as a reference. This means that when value of that parameter is changed in the method, it gets reflected in the calling method. An argument that is passed using a ref keyword must be initialized in the calling method before it is passed to the called method.

 

Optinal parameter - A method with an optional parameter can be called with only some of its parameters specified. Each optional parameter has a default value as part of its definition. If no argument is sent for that parameter, the default value is used.