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We'll come back.

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And this video, I would like to show you the functionality and called late in it and then also how

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setters and getters work.

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So let's create a variable called owner and it's going to be of type string.

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If you create such a variable, as you can see, you always need to initialize it and on alternative

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hereby is to use late in it.

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What do you say with this is that you will initialize it later on so you don't want to initialize it

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in here, but you will initialize it later.

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For example, in the init function.

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But there is something that you have to be very careful about when you do something like that.

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Because if I know, create an object of type car.

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So here bar my car is going to be of type car and now I want to access the owner.

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I'll get an error to be more precise.

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You can see I'm getting a initialise property access exception.

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So that's because of this late in a property owner has not been initialized.

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And it is, of course, because we use late in it and we're trying to access something that is empty,

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but it's not infallible, so we're not catching it.

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So what we will need to do is to use it in it.

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So the initialization of our car and in here we can set the owner through, for example, Frank.

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And now, to be more precise, you can even say this dot owner because we're talking about this property

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here.

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So if we run this again, then we will see there is no error.

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So it doesn't display anything because we don't have any print statements.

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But as you can see, it doesn't create an error anymore.

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So this is fine.

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This works only be careful that you don't use the variable before you have initialized it when you make

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it late in it.

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All right, the next thing I would like to show you is, let's say we have a brand for a car, so it's

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going to be a vault my brand and it's going to be of type string and let's say I assign BMW to it.

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Okay, now I'm going to create a custom getter, so I'm going to use get.

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And then I created Get Her Here, which will just return field dot to lower case.

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So what that will do is whenever somebody is trying to access my brand, so this variable here, what

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they will get is the lowercase version of BMW.

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So let's have a look at this.

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Let's actually use it here.

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So here, not the owner, but I want to have my brand, and that's in this case printed front line brand

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is.

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And then my car that brand now could see brand is BMW and BMW is written in a lowercase.

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Now, what did we do here?

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Well, what we created is a custom getter by default.

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Let's say we have a verbal called max speed.

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So this time it's not the ball, it's a VAR bar.

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VAR max speed is going to be of Typekit, and I'm going to say it's going to be 250 kilometres per hour.

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And by default, what happens is that Scotland creates the following code for us.

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So it says value field equals value.

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OK, so this is the default that is generated in the background.

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So when we create this variable here, this code here is automatically generated.

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We don't need to write it ourselves so we can just get rid of it because as you saw when we wanted to

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use something or as we can see here, so let me print a line.

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Max speed is and then we use my car max speed.

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As you can see, we can access it.

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So we are getting the value.

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We could even go ahead and set the value to 200.

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But we would need to do that before.

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So let me do that real quick.

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My car thud like speed is going to be 200, so now we set it.

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This is where we set the value and in this line we get to value.

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So we are retrieving it so that we are make speed is 200, even though it was 250 here by default.

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So bringing this back this jet and set what you can do is you can customize it.

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And we did that with this getter here for our BMW.

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So we did it here.

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We create this custom getter.

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And we can do the same thing with the senators.

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So if anyone tries to set our maximum speed, we can check if the maximum speed is at least positive,

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so we could even run an error here.

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So we can say field, if value is greater zero, then use value.

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Otherwise, throw an illegal argument exception.

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And we're just going to say maximum speed cannot be less than zero.

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All right.

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So what we have here is an if and else statement just in one line.

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But of course, you could do that in multiple lines.

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But basically what we're saying here is that if someone tries to set the maximum speed and they tried

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to set it to a lower value than zero, then throw an illegal argument exception, which is just going

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to say max speed cannot be less than zero.

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OK.

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As you can see here, this get field.

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This is not a custom field, so it's just this redundant getter because we're just using the default

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getter here.

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So of course, we could get rid of this whole line here.

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All right.

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So let's try it.

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Let's set the max speed to minus five just to get this error.

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So I'm running it.

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And as you can see, I'm getting an illegal argument exception.

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Max speed cannot be less than zero.

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So it's basically the text that I defined here for our illegal argument exception.

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What happens if we said the positive value here, let's say two hundred forty?

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Then we see the max speed is 240.

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All right.

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So this is what you need to know about setters and getters.

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There's one more thing that I would like to show you, though, and that is, for example, if you have

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a model.

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So I'm going to create another variable here for my model that's going to be of type string and I'm

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going to assign them five to it.

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OK.

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So of course, this would be redundant.

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We don't need that, but I'm just going to keep it there.

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So what I can do here is I can make the setter private.

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So we have seen this private keyboard before, but we have not used it.

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What does private do?

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Well, private says that the something is only available within the same class.

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OK, so in this case, it will only be available within the car.

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So if I try to access my model and try to set it somewhere else, it's not going to work.

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So let's just try it.

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Let's go up there in our main function and go to my car and then try to set my model to something like

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I'm three.

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So as you can see, we're getting an error here, Kenneth assigned to my model.

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The setter is private in car.

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To get her, however, is not private.

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So if we want to print the car model, print and model is and then we use my car model.

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And here you can see I don't get an error here because the getter is not private.

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Only the setter is private.

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So what I did here is I said, OK, you can only change the value of my model within the same class.

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So, for example, in our in it.

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So here I could say this my model is going to be and I'm three instead.

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So this will work.

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And if I run this, I will be able to get my model and it will now be an M3 instead of one.

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And I'm five.

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So there we are, modellers and free.

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All right, one little thing that you might have questions around is what this field and this value

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are.

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Well, field is a backing field, which helps you to refer to properties inside the getter and setter

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methods.

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This is required because if you used a property directly inside together or setter, then you run into

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a recursive call, which will generate a stack overflow.

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So this is just a syntax that you need to use when it comes to fields and value.

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Value is the value that is given to the variable when you set it.

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So here for max speed, for example, this 240 is the value.

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So whatever is after the equals sign is going to be the value that is set.

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So you can do something like double check what the value is that is given to you and then you can adjust

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accordingly.

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And then whatever is the result of this will be then set back to the field, which means just back to

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the variable itself.

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All right.

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So that's setters and getters and also late in it.

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And in the next video, we're going to see a little more about object oriented programming.

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So see you there.