/* eslint-disable func-names */

// START:instance

function Coupon(price, expiration) {

this.price = price;

this.expiration = expiration || 'two weeks';

}

const coupon = new Coupon(5, 'two months');

coupon.price;

// 5

// END:instance

// START:prototype

Coupon.prototype.getExpirationMessage = function () {

return `This offer expires in ${this.expiration}.`;

};

coupon.getExpirationMessage();

// This offer expires in two months.

// END:prototype

// START:extend

class FlashCoupon extends Coupon {

constructor(price, expiration) {

super(price);

this.expiration = expiration || 'two hours';

}

getExpirationMessage() {

return `This is a flash offer and expires in ${this.expiration}.`;

}

}

// END:extend

export { Coupon, FlashCoupon };