Javascript 34.2: Adding methods

Question

I haven’t been utilizing “main()” as the concept was never introduced, and it confuses me. I’ve been working around it through all challenges. I cannot figure this one out though. My attempt is in the comments.

Answer 1

changePrice is a method of the Product function that returns the discounted price, that is, product costs $5 and discounted costs $4.9

Answer 2

The return is not really needed Fan Mason . You can see this here:

https://code.sololearn.com/WTK68kk8ILHs/?ref=app

Answer 3

var x = readLine();
var y = parseInt(readLine(),10);
var z = parseInt(readLine(),10);

function Product(prodID, price, discount) {
this.prodID = prodID;
this.price = price;
this.changePrice = function(discount) {
this.price = price - (price * (discount / 100));
}

}
var prod1 = new Product(x, y, z);

console.log(prod1.prodID + " price: " + prod1.price + "\n" + prod1.prodID + " new price: " + prod1.changePrice(z));

Answer 4

Your changePrice method returns nothing.

Answer 5

Hint: the prices change of prod1 should be done with the function changePrice (a setter function):

console.log … „old price“
prod1.changePrice(price - (price*discount/100));
console.log … „new price“

Answer 6

After adding return, the script is eorking Vasiliy and JaScript. Thanks, both of you. However, why is changePrice only a function of discount and not price too?

Answer 7

I mean why isnt it thischangePrice = function (price, discount) instead of just thischangePrice = function (discount)? Vasiliy

Answer 8

Fan Mason changePrice is a method of Product class, "this" is a reference to the object, and price is an attribute of the object. So method changePrice can already access price from object attributes, not needing it passed in.

Answer 9

function main() {
var prodID = readLine();
var price = parseInt(readLine(),10);
var discount = parseInt(readLine(),10);

var prod1= new Product(prodID, price);
console.log(prod1.prodID + " price: " + prod1.price);

prod1.changePrice(discount);
console.log(prod1.prodID + " new price: " + prod1.price);
}

function Product(prodID, price) {
this.prodID = prodID;
this.price = price;

this.changePrice = function(discount) {
//your code goes here
this.price = price - (price * (discount / 100));

}
}