'use strict';

function Rect(x, y, width, height) {

this.x = x;

this.y = y;

this.width = width;

this.height = height;

}

Rect.prototype.toString = function() {

return `[${this.x}, ${this.y}, ${this.width}, ${this.height}]`;

};

function Square(x, y, side) {

Rect.call(this, x, y, side, side);

}

Object.setPrototypeOf(Square.prototype, Rect.prototype);

// Square.prototype = Object.create(Rect.prototype);

// Square.prototype.constructor = Square;

// Square.prototype = new Rect();

// Square.prototype.constructor = Square;

// For node.js

// util.inherits(Square, Rect);

// Usage

const p1 = new Square(10, 20, 50);

console.dir(Square.prototype);

console.dir(p1.prototype);

console.dir(p1.constructor === Square);

console.dir(p1.__proto__ === Square.prototype);

console.log(p1.toString());