How to create an object in JS?

Question

JavaScript

Good afternoon.

Tell me how to create an object in jS?

If specified as:

let user = {
  name: "John",
  age: 30,
};

That is mutable data.

And I also want to add data that cannot be changed, like this:

const user = {
proff: "ingeneer"
};

And tell me how to unite (and is it possible to do so) to specify what will be immutable and what is mutable for this object?

Thank you.

Answer 1

Probably somehow using private variables:

class User {
    #proff;

    constructor(name, age, proff) {
        this.name = name;
        this.age = age;
        this.#proff = proff;
    }

    get proff() {
        return this.#proff;
    }
}

const my_user = new User('name', 29, 'luftwaffe');

console.log(my_user.age); // 29
my_user.age = 92;
console.log(my_user.age); // 92

console.log(my_user.proff); // luftwaffe
my_user.proff= 'kriegsmarine';
console.log(my_user.proff); // luftwaffe

You can also use defineProperty and writable: false, but this is somehow not very beautiful