Java declaring a variable which implements an interface

Question

this is my first question I ask here so I might do some things wrong.

I wish to declare a variable which I know is of a class which implements an interface.

private <T extends Executable> T algorithm;

This was my attempt to achieve the goal

Answer 1

You don't have to use generics for that. The following will work for any sub-class / implementation of Executable:

private Executable algorithm;