Make sense of objects

- JavaScript is technically an object-oriented language, although if you come from another object-oriented language, you'll find JavaScript to be pretty sloppy. Nevermind that. JavaScript's loosey-goosey attitude towards object orientation is a feature, not a bug. We've dealt with an object earlier in the course when I introduced you to the Array. Objects are used when we want to create a cluster of related data for something, and maybe perform some actions or operations on that data. In a more formalized sense, objects are data models that allow us to combine properties and methods for a specific data set in a structured way.

The easiest way to make sense of this is to create an object. The course you're watching right now is a good candidate for an object. It has a bunch of different pieces of data that all relate back to the course, and we should be able to access all of, or any piece of that data at any time by simply referencing the course. If I were working with a single course, I could use variables, but if I had a list of courses, I'd have to use a multi-dimensional array, and even then it could become very hard to manage, very quickly.

Using an object, we can setup a model for the course data, and then create custom methods to be used on any defined course object. First, we create the course object, which is assigned to a variable, and define it as a new object. var course = new Object(); with a capitalized "O" and two parenthesis afterwards. Next, we setup the object properties. These are essentially variables associated with the object.

So, course.title = "JavaScript Essential Training"; course.instructor = "Morten Rand-Hendriksen" course.level = 1; for beginner, course.published is the published status, so true, since you're watching the course right now. And course.views is zero, because no one's watched the course yet. I can also do this using a shorthand, var course = { title: "JavaScript Essential Training", instructor: "Morten Rand-Hendriksen", and so on.

Now I can retrieve the entire course objects by simply calling it, console.log(course); and I can retrieve any of it's properties by specifying that property, console.log(course.title); objects can also contain methods, functions that use of change the data in the object properties. For my course objects, I may want a method for updating the views numbers anytime someone views the course. So I create a new method called, updateViews that contains an anonymous function.

Inside the function, I return ++course.views; Now, rather than a bunch of disjointed variables and functions, we have a single contained object called course with the properties title, instructor, level, published, and views. And the method, updateViews, which updates the views number.