ES6 Class Multiple inheritance

Question

I've done most of my research on this on BabelJS and on MDN (which has no information at all), but please feel free to tell me if I have not been careful enough in looking around for more information about the ES6 Spec.

I'm wondering whether or not ES6 supports multiple inheritance in the same fashion as other duck-typed languages do. For instance, can I do something like:

class Example extends ClassOne, ClassTwo {
    constructor() {
    }
}

to extend multiple classes on to the new class? If so, will the interpreter prefer methods/properties from ClassTwo over ClassOne?

Answer 1

An object can only have one prototype. Inheriting from two classes can be done by creating a parent object as a combination of two parent prototypes.

The syntax for subclassing makes it possible to do that in the declaration, since the right-hand side of the extends clause can be any expression. Thus, you can write a function that combines prototypes according to whatever criteria you like, and call that function in the class declaration.