Use getters and setters to Control Access to an Object--

Use getters and setters to Control Access to an Object--


Tell us what’s happening:
I don’t understand classes and constructors in javascript. Please help me.

Your code so far

function makeClass() {
  "use strict";
  /* Alter code below this line */
   class Thermostat {
     constructor(temperature) {
        this.temperature = temperature;
        get temper(){
         return 5/9 * (temperature - 32);
        set temper() {
         return F = temperature * 9.0 / 5 + 32;
  /* Alter code above this line */
  return Thermostat;
const Thermostat = makeClass();
const thermos = new Thermostat(76); // setting in Fahrenheit scale
let temp = thermos.temperature; // 24.44 in C
thermos.temperature = 26;
temp = thermos.temperature; // 26 in C

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge:


Your getter should be written something like this:

   get writer(){
     return 5/9 * (this.temperature- 32);

And your setter

   set writer(newValue){
     this.temperature = newValue;


Getters and setters are for accessing/mutating an internal private variable. In this case, they should be called temperature, the internal variable should be called something else.


This challenge is teaching two types of functions: Getters & Setters.

  1. Getters: are functions that only return the values of properties of your choice which are set in the constructor.
  2. Setters: are functions that update the properties of your choice which are set in the constructor.

I’m going to break down the following code:

class Book { 
  constructor(author, title) { = author;
     this.title = title;

In this part you notice a class named Book, containing a function called constructor. that function is called constructor function. its use is to allow creating a new instace of Book class.

Let’s say, I have a book named: David Copperfield by Charles Dickens. to create a new instance of Book for this, I write the following:

const charlesDickens = new Book('Charles Dickens', 'David Copperfield');

I created a new instance of Book and stored it in charlesDickens.


  1. The this refers to the current class.
  2. The author and title variable will store the values received from author and title arguments of the constructor function.

What if I want to return or print the author and the title of the book (without allowing direct access to the constructor)?

What if I want to allow myself to update the author or the title of the book at a later time (without allowing direct access to the constructor)?

What should I do?

All can be set inside the constructor function, but if I want to restrict access to the constructor and want only a variable or two to be returned, modified, printed…: Getters and Setters functions will be of great help.

I hope this was helpful.

and Happy Coding!


Thank alot, I will review this later


Now, I understand that getter is using to return any values property from a constructor. Where as setter is used to change any values property in a constructor property. Now let me try to solve the challenge. Thank you.


@clevious,@DanCouper,@Tchoukoualeu: Thank you very much. I used your information and I did it just fine.


You’re very welcome.

Good luck & Happy Coding!