Java - what is a a prototype?
java
Solution
I think the use of the word prototype in this context is unfortunate, some languages like JavaScript use something called prototypical inheritance which is totally different than what is being discussed in the lecture. I think the word 'contract' would be more appropriate. A Java interface is a language feature that allows the author of a class to declare that any concrete implementations of that class will provide implementations of all methods declared in any interfaces they implement.
It is used to allow Java classes to form several is-a relationships without resorting to multiple inheritance (not allowed in Java). You could have a Car class the inherits from a Vehicle class but implements a Product interface, therefor the Car is both a Vehicle and a Product.
Problem
In a lecture on Java, a computer science professor states that Java interfaces of a class are prototypes for public methods, plus descriptions of their behaviors. (Source https://www.youtube.com/watch?v=-c4I3gFYe3w @8:47) And at 8:13 in the video he says go to discussion section with teaching assistants to learn what he means by prototype. What does "prototype" mean in Java in the above context?