To define class in es6, you can do this

class A {
    x = 1;
    y = 2;
    z = 3;
    mx () { // ... }
    my () { // ... }
    mz () { // ... }
}

When there are more and more A class attribute methods, it is found that the entire file has a large amount of code. Can some properties and methods be divided into a single file (for example, x and mx are divided into one x.js file, y and my are divided into one y.js file...)

If you use extends, you will find a problem. Properties cannot be shared, and neither can methods.

Can we combine (x.js / y.js / ...) into A when defining class A?