JavaScript objects are very simple collections of name-value pairs. There are two ways of creating a simple object in JavaScript. The first way is as follows:

var obj = new Object();

And the second way is as follows:

var obj = {};

We can also create an object entirely as follows:

obj = {
    name: {
        first: 'Gandalf',
        last: 'the Grey'
    },
    address: 'Middle Earth'
};

In object-oriented programming (OOP), an object is an instance of a class. A class defines the characteristics of the object. For our algorithms and data structures, we will create some classes that will represent them. This is how we can declare a class that represents a book:

function Book(title, pages, isbn){
    this.title = title;
    this.pages = pages;
    this.isbn = isbn;
}

To instantiate this class, we can use the following code:

var book = new Book('title', 'pag',  'isbn');

Then, we can access its attributes and update them as follows:

console.log(book.title); //outputs the book title
book.title = 'new title'; //updates the value of the book title
console.log(book.title); //outputs the updated value

A class can also contain functions. We can declare and use a function as the following code demonstrates:

Book.prototype.printTitle = function(){
    console.log(this.title);
};
book.printTitle();

We can declare functions directly inside the class definition as well:

function Book(title, pages, isbn){
    this.title = title;
    this.pages = pages;
    this.isbn = isbn;
    this.printIsbn = function(){
        console.log(this.isbn);
    }
}
book.printIsbn();

Now we have covered all the basic JavaScript concepts that are needed for us to start having some fun with data structures and algorithms!