Question

I am going through an example and I am not sure why they are doing this.
They are setting mySender to with IEmailSender….

IEmailSender mySender = new MyEmailSender();

why not just write

MyEmailSender mySender = new MyEmailSender();

as MyEmailSender already has the IEmailSender interface reference

Answer 1

Later in the code they could write

mySender = new MyNewEmailSender();

if necessary. But it isn’t necessarily right or wrong. They’re just trying to get a point across, mySender is an IEmailSender regardless of the implementation.