NP52 Two objTwo = Two.New();

Question

Hi Guys NP52 Two objTwo = Two .New(); http://www.c-sharpcorner.com/UploadFile/rmcochran/instantiationFactory06232007153242PM/instantiationFactory.aspx In the article (website address is given above) there is a following part: In this scenario when we want to new-up our class we call it through the static method as follows: Number objTwo = Two .New(); The following code would not compile because the New() factory method now returns a Number object and not a Two object: Two objTwo = Two .New(); There is an error. Two objTwo = Two .New(); must come instead of Number objTwo = Two .New(); And Number objTwo = Two .New(); must come instead of Two objTwo = Two .New(); I wish to confirm whether I correct or not. Please confirm it. Thank you

Maha · Answer

Thank you Alan

Alan · Answer

I think the article is in fact correct Maha. When instantiating a Two object you now have to call the Two.New() method which returns a reference to a Number not a Two. In other words although its a Two object its implicitly converted to a Number reference which is OK because Number is the base class. You therefore need this line: Number objTwo = Two.New(); The following line won't compile because there's no implicit conversion back from Number to Two: Two objTwo = Two.New(); However this will work at both compile time and runtime: Two objTwo = (Two)Two.New(); //explicit conversion to Two