//ES6 Modules : used with browser : by default everything in this file is private

//Implementation details: hidden: private properties

const _radius = new WeakMap();

const _move = new WeakMap();

const privateProps = new WeakMap();

//Public Interface: exposed

export class Circle{

constructor(radius){

privateProps.set(this, { //not recommendable but can do like this(better will be seperate each properties as a weak map)

radius:radius,

move:()=>console.log(this, 'move')

});

_radius.set(this, radius);

_move.set(this, /**function(){

console.log('move', this); //here 'this' will undefined because body of the class execute in strict mode

} */

()=>console.log('move', this) // if we use arrow function then 'this' will be the Circle object

);

}

draw(){

console.log(_radius.get(this));

}

move(){

_move.get(this)();

}

//Getter : Poor approach : for better approach

getRadius(){ // in this getter approach we need to call getRadius() method every time

return _radius.get(this);

}

/**Getters and Setters */

//Getter: better approach : ES6 classes

get radius() {

return _radius.get(this);

}

//Setter: better approach : ES6 classes

set radius(radius) {

if(radius<=0) throw new Error("invalid radius");

_radius.set(this, radius);

}

}