how to get value of Class.js in android

Question

i have a class model .js So, how to get value from this class in android project

class Polygon{
      constructor(height, width) {
        this.height = height;
        this.width = width;
      }

      get area() {
        return this.calcArea();
      }

      calcArea() {
        return this.height * this.width;
      }
}