constructor.js

const instanceFactory = (x) => {
	this.a = 10;
	this.b = x * 5;
	this.c = () => {
		return a + b;
	}
}

const instance = new instanceFactory(3);
// basically returns an object with the following values appended to this.

instance.a; // 10
instance.b; // 15
instance.c() // 25