Manipulating Objects in Classes in OOP in JavaScript

Classes can accept objects of other classes as method parameters and manipulate these objects. Let's look at an example. Let's say we have the following class:

javascriptclass User {
  #name;
  
  constructor(name) {
    this.#name = name;
  }
  getName() {
    return this.#name;
  }
}

Let's say we decide to make a class that will manipulate a set of objects with users:

javascriptclass UsersCollection {
  
}

We will store objects with users as an array in a private property:

javascriptclass UsersCollection {
  #users;
  
  constructor() {
    this.#users = [];
  }
}

Let's make a method for adding a new user to the array:

javascriptclass UsersCollection {
  #users;
  
  constructor() {
    this.#users = [];
  }
  add(user) {
    this.#users.push(user);
  }
}

Now let's make a method that will output the names of all users to the console:

javascriptclass UsersCollection {
  #users;
  
  constructor() {
    this.#users = [];
  }
  add(user) {
    this.#users.push(user);
  }
  show() {
    for (let user of this.#users) {
      console.log(user.getName());
    }
  }
}

Let's take a look at how our class works. First, let's create an object:

javascriptlet uc = new UsersCollection;

Now let's add some users to our collection:

javascriptuc.add(new User('john'));
uc.add(new User('eric'));
uc.add(new User('kyle'));

Now let's call a method that will output the names of all users to the console:

javascriptuc.show();