Hello, welcome back to the next one. So, in the last class we talked about classes, we, we created a class we try to understand a little bit about objects, what objects are. And then we created these private class or member variables, we can see them or fields we can say them. In this one, we will see how we can use these member variables, why we made them private, what our getters and setters in the class concept and how they are utilized and why we declare them or define them in the first place. So let's go to the tutorial source concept. And I'm just going to create one more class right click new class.

I'm going to call it as class demo. So always notice that I append or prefix something, when I say when I use key words, right? So we should never use key words. Like class arrays, strings for the classes that we are creating, because these things already exist in Java. And we will have issues with that. Now I want to define the main method because I'll be creating the object of the car class, right click Finish.

And here I do have my class demo. Now what do we want to do? We want to create the object of the car class. So I'm going to say car. This is the type that we want to use. So car class, I'm creating the object first.

So I'm going to use car then I'm going to name and give a name to it. So which is usually the reference. Let's say BMW equals to new so new is the keyword to create an initialize the object. This is the most important thing, and again, car and parenthesis. This is our syntax to create the object of the class, straightforward. It's very simple.

So I'm just going to say create and initialize the object, right? Now let's take a look. If I say BMW, the reference, and if I put dot here. Oops, looks like a little slow. Again, let's do I see a bunch of methods equals get class hashCode. increase speed, increase speed is something that we defined here, right?

But what are other of these things that we haven't defined? So these things are actually coming from object class? Do you see that object OBJ. So even if they don't have any arguments to accept, but these things are coming from the object class, you can see up there, right? This is from object object, object object. This is by default in Java, every single class we create, kind of implicitly, we don't even know about it, but it kind of inherits from the object class.

And do not worry about when I'm saying inherits. We will talk about inheritance later in future lectures in detail in this course. So don't worry about it. But yes, every class kind of inherits from the object class. So but yes, when we put.bc, all the methods also that we have defined, right? But you must be wondering that I don't see anything about the fields.

The reason is, because these are private if I make one of them as public. And if I then try to access lt, the make is here, which is string and it's from the car. So at the end, you'll see from it, it's coming. It's from the car class. And this guy increased speed is from from the car class, so we'll see them. But we don't want to do that.

Let's again make it private. Now we understood that this is how we can access the stuff from the Car Club. In any other class where we want to use it, and this is how it works with the use of a car object reference. Now, what we want to do here is we want to create getters and setters, so getters and setters, I will say just do not go in the name at all. I mean, don't think these are something special, do not get confused with them. Do not think it's something very tricky.

They are just simple methods. And I'm going to show you what they are. So right now let's say I want to create a setter. setter means a method which is used to set the value of a field or a variable. That's about it. So we're going to create a method like public set make.

So I'm calling it set make because I want to set the value of the make field. That's why this method is known as setter because it sets the value And I want to define it as void because it does not return anything. And since it sets the value of make and make is a string variable, I want to accept the string argument to it and string make, right. So this is the method. Here comes another problem that we'll just see. So I want to set the value of make and I'm accepting an argument called make.

Now this make and this make a same, not same as a variable name is same right? Now if I say, make a equals to make, what am I doing? It's actually referring to this variable only. It's not referring to this variable when I'm setting the value because inside a method, always the closest argument or the closest variable is referred the method does not know about this it knows about this, but inside it It always refers the method with this one. So, it only happens when the method sorry, it only happens when the variable names are same, let's say I just called as ma k right. Now, I can say I make a and make you can see that the color also change this make is now this blue one.

And this m AK is equals to this one. Now, it is actually referring to this make because it cannot find any other variable with the name make inside this set make method. But we do not necessarily want to do that. We want to use the names that we like, which makes more sense. So what happens is we use a keyword called this. This keyword is a special keyword in Java.

What it does is when we put this in front of the variable it access Is the member variable or the class variable. So whatever we define here, this dot make is gonna be this. So now, the variable make here you can see the color coordination also these two are same, they both are highlighted. And when I go here, these two are highlighted. So the color combination of them are same. So this key word is now referring to the make hair.

And this make Sorry, I'm using this and the key word is also is this. So don't get confused by that. But yeah, the make hair is actually same as the snake. So this is the keyboard which is used to access the class and member variables. Now when we create like 10 objects of this class, the car class, this keyword is going to help assign the correct values to these variables for different objects. And we'll see that thing also shortly.

So now we saw what a setter method is, we saw how we set the value. Now let's define a getter method also, so public. And let's return the make only. So I'm just gonna say string, get make. And since this is a, make as a string, I'm defining the return type as string. And it should be just return this dot make.

Right? So air is gonna return the value of make variable. Now what we can do here is I'm gonna say BMW dot set MC equals to B MW. And what we can do here is we can just quickly use a print statement, and we can say, p m, double W, this is the name of the reference and now we can see that Get make method get make and other. So what this car is going to help us with this is going to help us get the value of make. So run this as Java application, right click.

And we can see here at the bottom that we got the make as BMW. Well we can do here is BMW, sorry, we have to define others Alright. So similarly we can define getters and setters for all the variables, all the member variables we have, and that we want to use outside the class right. Now there is a shortcut to do that. You can right click, go to source and go here, generate getters and setters. I'm gonna click this.

It's gonna bring me color model here. You can select whichever variables you want to do. It's not even presenting me make because I've already created insertion point is after Get make method I want to do. So it's all in the proper format, sort by getter setter pairs, which is good. Every method should be public all good. So I click OK. And boom, there you go at the bottom, it has automatically created, get color set color, get model, set model, get here, set it all the methods for us, right?

And set it is associating, like, get and set. So let's reorganize the make also, right. So this is how we can create getters and setters automatically as well. So this is really cool, right? So I think that's about it. Let me go to the next lecture.

And I'll continue the discussion on this. And we'll see a little bit more about the getters and setters, and how do we access them and why we really created the getters and setters. So thanks a lot for joining This one and I'll see you in the next lecture. Thanks