Let's see. I have to make a homework with a complicated UML diagramm. I have an interface called Q, and a class called W, which realizes the Q interface. I have another class called R, which extends from W.
The question is: Does the class R realize the Q interface?
Thank you guys!
1) Implementing an interface (Q) is a contract stating that your class contains certain methods. 2) When you make a subclass (R), all methods from the super class (W) are inherited by the subclass. 3) So..what do you think?
If you have an interface Q
interface Q {
void say();
}
and a class W which implements Q,
class W implements Q {
public void say() {
System.out.println("Hello");
}
}
and a class R which extends W
class R extends W {
}
Then yes, R also implements Q. You could potentially say,
Q q = new R();
q.say();
If you're asking: "Does each subclass have to re-implement the interface?" the answer is no. If the superclass implements the interface, the only reason to re-implement it in a subclass is if you need the subclass to do it differently than the superclass.
