Hi guys, I am having trouble understanding what "this.name = name;" means. What does each word do?

Hello Kashish!

I'll try to answer best I can for you.

The 'this' keyword is a bit of a JavaScript gotcha. It is covered in a course here in the JavaScript library, but to get you started the 'this' keyword is commonly used in Object in Javascript that is the prototype for a new Object.

You may be familiar with the format of object literals in JavaScript. Taking a dog for example we could make a dog object like below literally.

var dog = {

  name: 'sally'
  coat: 'smooth',
  breed: 'dashhound',
  bark: function(sound)
                {
                        console.log(sound);
                }

}

The above creates a dog object, it has three object properties. name, coat and breed. You can access these using the dot notation. For instance javascript console.log(dog.name); The dog object also has one method (The name for a function inside an object) called bark: accessible like so: javascript console.log(dog.bark('Woof'));

Notice that when we created the dog object and gave it a method (function) called bark we provided it with a 'sound' parameter in the parenthesis, then inside the method (function) we supplied console.log() with the sound argument again, this means that when you declare dog.bark(); you'd include a string for the dog to make a noise, you could for instance use console.log(dog.bark('oink')); to the same affect.

But what if you wanted multiple dogs, all with similar properties and methods, but each needed to be different. That's where 'this' will come into play.

Rather than declaring an Object Literal inside a variable as above, what you do instead is create a constructor function (Factory, Prototype - they have many names).

function Dog(name, coat, breed, sound){

      this.name = name;
      this.coat = coat;
      this.breed = breed;
      this.bark = function(){
                console.log(sound);
       }
}

Notice above the first difference is that we declare the object with a function, as this is now our factory for creating other objects, based off this prototype.

To make it clear that your function is for the creation of objects and not part of your programs logic it's good practise to name your object with a Capital letter.

Then like before parameters are passed into this function, then notice that instead of providing key value pairs literally like before, we say 'THIS' which refers to the object and then we use the dot syntax to provide a parameter or method.

This is where your this.name = name; comes into play.

All that is being said is that THIS objects 'name' property will equal the value of whatever is passed into the function when the object is created.

I hope this helps.

Oh, and one more thing, just to illustrate a complete object like this and how we'd create it.

function Dog(name, coat, breed, sound){

      this.name = name;
      this.coat = coat;
      this.breed = breed;
      this.bark = function(){
                console.log(sound);
       }
}


var myDogOne = new Dog('Mr Wiggles','smooth', 'Dalmatian','YAP' );

console.log(myDogOne.name);

//The console logs 'Mr Wiggles'