Welcome back to the second link demo.
In this demo we are going to prepare a bunch of stuff which we will need later on.
So first of all, we are going to create two additional classes and then actually third one which will
handle those two classes.
So those two classes that we are going to create, they should be used to create objects of those classes
and they are using universities and students.
So let's create a new class in here.
And yes, I know you should create classes on the right hand side.
Well, you should create specific files for every single class, but I'm going to create it in here
in the same file in this program, CSS file, because it's easier for you to follow along.
But otherwise you should always go like this.
Create new and then class, and then you should go ahead.
All right, so add class and this one will be university.
So every university has certain information about itself.
So what should a university have?
Well, let's start with an ID.
So I'm going to say it has an ID and this is a get and set property, a very basic property.
Then I create another property and this time like this, it's going to be a string time called name.
So every university has an ID and a name, nothing too fancy.
Right?
And then the only thing that we have to do in here is just print something.
So we're going to create a method in here which is gonna be called print, and it's going to print out
details, or we could call it show info or something like that.
The only thing it's going to do is write something like University zero with ID one and zero will be
the name and one will be the ID.
All right, so that's our university class.
And now let's create a class for students.
So class student.
So every university has students, right?
And we want you go ahead and have an ID for the students as well and ID get and set then a string called
name.
So every student has a name cut and set and then actually let's do it with prop double tap string and
every student has a gender.
And then finally we add one more property.
So prop and this time it's going to be the age.
So every student has a specific age.
And then here there is one important thing because every student has a foreign key, because if he's
not at the university, he's not a student.
So let's assume that.
So we need to have a foreign key.
Foreign key and that will be our public int university ID.
So a student belongs to a specific university ID.
All right.
And we finally also just print something onto the console.
So public void print and it's just going to print something like.
CW Double tap student
zero with ID one, gender two and age three from university with the ID four.
And now of course need to use all of those properties.
So it's going to be name ID, gender, age and university ID.
And as this is a little long, I'm going to put it on the second line like that.
So this is going to be the print statement of the student class.
Now, in order to manage students and universities in the linkway, we will create another class.
And this additional class is going to be our university manager.
So it's going to handle universities, it's going to add members to the university, so students to
the university.
Then it's going to show us all the male students, all the female students and those kind of things.
So let's create a new class for that, and I'm going to call it Class Uni.
Our city manager.
And then here I want to have lists to work with.
So first of all, I have a list of university, so of our university type that we had and I'm going
to call that university.
And then another list, public list called student, which is going to be our students.
So this list is full of students, this list is full of universities.
And now in a constructor, we will initialize those two lists and we will add values to them.
So let's go ahead and create a constructor public university manager like that.
Now, that's our constructor, right?
Constructor.
And in here, I want to go ahead and initialize my university.
So it's going to be a new list of university
and my students, which will be a new list of student.
And now we can go ahead and add values to them.
And I'm not going to type everything manually.
I'm just going to copy and paste from the list that I've prepared.
So let's assume we have two universities.
One is Yale, and the other one is Beijing Tech.
And then we have let's some students here, which is Carla, who's female.
She's 17.
Then there's Toni, he's male, he's 21.
And those two, they are at Yale and then the other university.
So at Beijing Tech, we have Lila, which is female, then James, who's transgender, and then we have
Linda, who's female.
All right.
So we have three different here, three different genders.
All right.
So this is our university manager constructor so far.
And now we can go ahead and add some methods which will actually do some link things because we haven't
used link in this video yet.
So let's go ahead and do that.
Let's create.
A method which will give us all the male students.
So let's create that.
And here I'm going to use I enumerable so a list of students and I'm going to call it male students.
And now we use the same thing that we did in the last video.
So from student in students where student gender is equal to male and finally select student.
All right.
So that's how we create this list.
We have seen it in the last video.
We check out a specific list.
In this case, it's a actually list because so far we have seen that with a raise.
But you can do that with lists as well.
So that's pretty cool.
As you can see, collections, generic list and we can do that with this link approach here as well.
So now let's print that on to the console.
See, W is going to be male students and then finally, let's give us all the students.
So we're going to use a for each loop here for each student, which is student in male students, because
as we know, our male students are of type student.
So now we can go ahead and call the student dot print method.
All right, now let's go ahead and use this method, because so far we have only prepared and type code
and type code, and now it's time to finally run the code and see what's going on.
So let's go ahead and create a university manager object.
Let's call it, um, and let's initialize it straightaway, which is a university manager like that.
And now I can go ahead and use, um, dot male students.
So this method here and finally let's also write onto the console.
So console dot read key so that our program doesn't just shut down.
All right, so let's run it.
And we see here male students well, we have student Toni with the idea of one gender male age 21 from
university with the ID one.
All right, so let's check it out.
We have this one male student here, so let's copy and paste the male student just to check if there
can be two.
So this one will be frank.
And Frank is male, but he's 22 years old and he's at the second university as well.
So everyone is at Beijing University as it seems.
So let's run the code again.
And then we are we see both rows, so we see Frank and we see Tony.
So Frank is from University one and Tony?
Well, actually, Tony is from one and Frank is from two.
All right.
So now you see this method worked fine.
Now please go ahead and create a method that does the same thing.
But for women.
So we're just going to print out all the female students from the different universities.
All right.
I hope you tried it.
So I'm going to type it this time.
Public void.
Female Student And I need an I enumerable again, which will be of type student.
So a list of students which is going to be a female student's list.
And I want to check from all the students.
In students.
So this is, as I said before, each loop here basically.
And we want to check all the students where the gender is female and we want to select those students
and put them into our female students.
I enumerable Now we can write that on the console, so w and female students
and then we use a for each loop like that it's going to use student called student and the collection
called Female Students.
And now in here we're just going to use student dot print.
So now let's check out the female students.
So u m dot female students method.
And I know that this name is not perfect.
It could be something like show female students or filter by female students or filter by male students.
But I'll just keep it simple here.
And we are female students Carla, Layla and Linda with ad1, three and five, age 17, 19 and 22.
And they are different universities, as you can see here.
All right.
So now you have seen how you can create a bigger list in this case.
We are just using a list here with elements that we have added.
So you have seen how you can do that with arrays, how we can use link.
So this statement here with the race and also with lists and you can use the same thing with enumerable
as with well generally list types, right?
And also of course with tables and with XML.
And that's something that we will see later on.
So let's go ahead to the next video where we will extend our class here.
So our university manager class, which will well, show us some more information because so far we
only see students, male and female.
But what if we want to filter it by different information or if you want to sort it, stuff like that,
that's something that we will cover in the next video.
So see you in the next video.