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‫Welcome back.

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‫In this video, we are going to keep on going with properties and setters and getters.

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‫We started off on the last video where we looked at setters and getters and now we're going to use the

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‫same code and we're going to extend it a little bit.

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‫So we saw that we can use setters in order to set the value of a member variable and we can implement

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‫our own logic how we want to set it.

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‫So we can say, okay, if you want to set the value, it has to follow my rules so we can define our

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‫own rules, which have to be.

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‫Followed.

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‫And then we have getters which we can also adjust.

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‫So we can just say, okay, if you want to get the variable I'm going to give you in this case, the

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‫result of the multiplication of length, height and width so you can modify them to your liking.

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‫Now let's have a look at properties and how this is all connected with each other.

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‫So let's create a property and I'm going to create a public property called height, and this height

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‫will adjust my height member variable.

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‫So it was public before.

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‫Now I'm going to make it private so that we cannot access height from outside.

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‫So here, if I want to adjust height, I will not be able to do it any more.

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‫Now I get this error.

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‫All right?

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‫Now let's use our height property in order to still be able to access our height up there.

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‫So how do we do that?

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‫Well, we, first of all, use this property with a capital H at the beginning.

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‫That's generally how you use properties.

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‫That's a convention and C programming.

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‫The properties start with the capital letter and now here I can create my getter and I can return the

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‫height and I can create my setter.

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‫And I can just set the height here to being, for example, the value that is assigned.

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‫Now, what is this value keyword?

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‫Well, what we're doing here is basically the same thing as we did before, where we set length and

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‫get length.

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‫But now our gateway, so to speak, is our property height.

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‫So if you want to access or change the height memorable, you have to do it via the property height.

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‫So now what you can do is you can set it at the value that you set will be set to the height.

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‫Now how does it actually look like when we go to our program now here if we try to set the height?

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‫By accessing the member variable directly, we cannot do it anymore.

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‫But if you access the property, as you can see, the height is available here and it's this tool icon

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‫that we can see here.

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‫So this is generally the icon that you have when you want to access a property and you can see this

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‫works.

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‫So we can set the height now and if we do so, this will or this for here, whatever is behind this

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‫equal sign or after this equals sign, that will be the value here, this value and it will be set as

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‫the height.

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‫So this value is pretty much the same thing as length as we had before when we created this set length.

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‫It's the same concept pretty much, but we it's just a shorter way of doing it, right?

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‫So here you can see if we wanted to have a setter, we had all of this code.

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‫Of course, we didn't need this code here.

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‫All right?

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‫But still, we had all of this code and now we have this super short code.

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‫So this is the setter.

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‫Of course here we can also adjust it.

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‫Now, let's say if value is less than zero, then we will set our height to be minus value and else

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‫it's going to be height, equal value.

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‫Now let's go to our program and I'll set the height to minus four.

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‫And at length that said that before because we created this error before.

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‫Right.

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‫And now let's set the height to minus four and let's run our code.

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‫And we will see that it works.

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‫So length is for height is for width is five.

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‫So why is that?

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‫Even though we set the value to minus four?

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‫Well, we said if the value of the height that you pass to me is negative, then I'm going to multiply

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‫it.

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‫So if the value is less than zero, I'm going to multiply it with minus one.

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‫So I'm gonna make it positive again.

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‫And if it's positive, then just make it or assign the value.

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‫Or if it's zero, it's fine as well.

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‫All right.

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‫So that is what we can do with properties.

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‫Now, this is an implementation of a property.

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‫Of course, what you can do is you can also just use the property without having a member variable.

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‫So this member variable that we have here could be something that is not required whatsoever.

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‫So we could just even skip that.

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‫So let's say I don't want to set the width as a member variable, I want to have it as a property.

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‫And now I'm going to show you another way to create a property.

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‫And this is a lot, lot faster.

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‫So you just use P, R, o, p, and then you double tap and this will create this property for you.

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‫Now you just can enter the type and I'm going to say, okay, it's going to be an integer.

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‫Then you press tab again and now you can give it a name.

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‫So I'm going to call this one width.

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‫Now what is going on here?

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‫Well, this is a code that is just understood by C sharp and it even was created for us automatically

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‫with our ID.

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‫Right.

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‫It just says get semicolon set semicolon.

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‫So this just means that it's just going to be a default getter and a default setter, which just means,

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‫okay, if you want to access width, you can just access it by using the width variable this property.

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‫And if you want to set it, you can also just use it.

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‫So what does it mean in our case?

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‫Well, it means that now we can access this property by just assigning a value.

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‫And if we want to write it out.

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‫So if we want to access it, boxes with is box dot.

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‫With.

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‫So here we can access the property directly.

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‫All right.

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‫So this is the difference here.

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‫So internally it's the same thing as if we created.

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‫The.

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‫With.

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‫Let's get back to this with let's have this member variable again.

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‫So internally it's the same thing as if I created this public end with and I'm going to comment this

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‫out for now and I have a getter so get I return the width.

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‫Or this dot with.

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‫And the setter where I said they start with with value.

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‫All right.

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‫So this is really.

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‫This.

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‫Code here is really just the same thing as this one.

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‫And internally, it's also what happens once you compile the code.

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‫So the compiler does that automatically.

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‫For us it just says, okay, if you have this line of code, I'm going to internally treat it as if

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‫it was this code that you have here, only that it's a lot shorter and it's a lot easier to create this

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‫code.

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‫All right.

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‫So I'm just going to comment this out because I really like this short approach that we have there,

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‫and let's comment this out like this.

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‫And I don't need this member variable anymore.

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‫All right.

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‫Because here we needed to remember variable because I set the width and in this case, I set the member

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‫variable width.

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‫I didn't set the.

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‫I cannot cannot set the width itself.

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‫So if I instead here would write with.

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‫And with if I now do that, what I create as a StackOverflow.

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‫So I constantly try to set something and it's going to be an endless loop here, which is not good.

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‫That's why I needed to remember variable for this example here.

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‫All right.

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‫But internally, it's going to treat it like this, like that.

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‫So it's internally treating it like the code that we have here.

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‫Only that it's a lot shorter for us.

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‫All right.

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‫So now a little challenge for you.

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‫Please go ahead and create a property for volume which surrounds it like we did with the width here.

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‫All right.

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‫So pretty much the same example that we had here, only that it's going to adjust the volume and not

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‫the width.

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‫So please try that.

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‫Create your own property, type it out.

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‫Don't make the short approach or use a short approach.

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‫All right.

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‫So for this to make sense, we first of all have to make our volume private and then we can create a

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‫property for our volume.

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‫So public int volume with a capital V is going to be get.

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‫Return volume and then set.

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‫This start volume is equal to.

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‫Value.

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‫So this is the property that we created for the volume.

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‫I hope you were able to do so.

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‫Of course, you just could have gotten rid of this volume altogether and created it the same way that

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‫we did with the width.

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‫It's a lot quicker, but I just wanted to show you that this is all so cool.

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‫Now, the.

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‫Important part hereby is that we can think about the volume variable or this property and why, or at

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‫which point does it make sense to change it or get it?

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‫Does it even make sense to do both of them?

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‫Because the volume is something that is calculated based on the width and height and length.

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‫Now, does it make sense to set the volume directly?

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‫Well, no, I would say so.

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‫I think setting the volume doesn't even make sense at all so we could get rid of this whole setter and

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‫only have a getter.

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‫Now, the volume itself, we never set the volume.

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‫It's always calculated.

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‫So does it make sense to just return the volume?

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‫Well, it really doesn't, because actually what we should do is here at this point, we should calculate

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‫that the volume is going to be the multiplication of length, height and width, you see.

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‫So now it's a lot more meaningful.

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‫So what we return with the volume is a lot more meaningful.

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‫If somebody wants to get the volume, that's what they're getting.

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‫Now, of course, we created a little bug here at the bottom or some get volume methods that we don't

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‫need anymore.

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‫And at the same time here, the width now is the property that we access.

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‫It's not going to be the.

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‫Remember variable anymore because we don't have it anymore.

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‫And of course, in our program CSS, we can now also adjust everything.

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‫So now we can access the width directly and we can access the volume property directly and not the volume

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‫member variable anymore.

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‫All right.

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‫So now let's do a final step here.

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‫And that is to add a constructor.

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‫So public.

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‫Box.

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‫INT length.

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‫INT.

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‫Height and end.

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‫Width.

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‫So now if we create a box, I want to have all of those values and the length that is given to me once

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‫the box is created should be this dot length.

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‫Then the height that is given, this dot height should be the height.

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‫So the height that is given this one should be the height that we have here, which is our member variable.

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‫And our width is the final one and this is the property.

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‫So we set it to the width that is given to us.

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‫Now, in this case, you might of course omit this, this keyword.

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‫You can just say width, because it's also obvious that we are talking about the property of this class.

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‫So you don't need this this keyword here.

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‫Now, an important thing that somebody asked and I wanted to really make this clear.

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‫So this dot length, equal length works, but length is equal to this dot length does not make sense.

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‫So this line here does not make sense because length is this part here, which is really just the parameter

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‫and it's the value that is given to us.

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‫So we don't want to adjust the value that is given to us, but we want to set the value of our property

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‫or of our member variable, and that's what we do here.

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‫So in this case, that's what we do.

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‫We set the value of our member variable.

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‫All right, now let's use this box.

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‫Let's create boxes now, because now we don't need to do all of that anymore.

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‫We don't need to set the values directly anymore, but we can set them in the creation of our box.

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‫So I'm just going to assign values three, four and five.

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‫So the length is three.

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‫The height or actually the height is four into width is five.

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‫And now if we run this, it will display the width and the volume for us.

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‫So there you are with this.

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‫Five volume is 60.

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‫All right.

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‫That seems to work.

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‫Now, what we can do is we can set the width by accessing our property.

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‫Let's say we set the width to ten now and we run this code again.

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‫And with the split with once again so we can see that the default value that was given is printed and

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‫then the new value that we set.

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‫So we set width to ten and now it says the width and it's calculating the width accordingly.

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‫So three times, four times ten is one on 20.

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‫It's the new volume.

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‫All right.

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‫Summoning it up.

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‫So what we did is we created, first of all, a bunch of member variables.

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‫We made them private so that no one except for this class itself can access them directly.

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‫So no other class can access them directly.

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‫They can only access them via our properties that we created or via our setters and getters.

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‫So we have the set length that get length.

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‫So if anybody wants to access the length variable, they have to go the way of using set length and

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‫get length.

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‫This is a totally valid approach and you will see that.

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‫And yeah, with those approaches you can define the logic that you want to be followed.

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‫If somebody wants to, for example, set a variable or if they want to get a variable.

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‫Now another way of doing it is to directly use a property.

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‫So if you use a property, you need to call it with a capital letter and then you can implement a getter

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‫and etc. but you can also just decide to either only implement a getter or only implement the setter.

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‫We're not, of course, implementing both of them here.

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‫You can also set the.

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‫Values directly, so you can either set the member variables.

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‫So this is what we did here by.

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‫So to speak, adding a gateway called Height, which is our property to our height that we created here

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‫at the top, which is our member variable.

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‫Or we just went the direct route where we just said, okay, we will directly have a very simple auto

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‫implemented property here and we don't need to have an extra member variable for it.

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‫We could have gone the whole way for all of those variables to only have properties.

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‫So we could have made it very simple.

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‫But just having three properties like.

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‫This.

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‫So getting rid of all of that and just have a public or apr0p double tap and, and this would be then

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‫the length would be just get set and then the same thing for the height and so forth.

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‫But I just wanted to show you all of the different ways that there are and all of the different ways

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‫that you will see.

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‫And most of the times when you see something or when you use properties, you will see them most of

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‫the time like this.

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‫So with the other implemented property, what is the easiest and fastest way?

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‫You will not need to use all of the different approaches that I showed you that is really important.

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‫You will not need to use all of the different structures, but in some cases you will need to implement

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‫the setter.

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‫In some cases you need to implement the specific getter, and now you know how to do it.

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‫So in short, if you have any questions, why would you need this approach?

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‫Well, they are just used when you have no additional logic required in the property assessors.

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‫So in the property definitions and yeah.

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‫Getters and setters.