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‫Welcome back.

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‫In this video, we are going to create our first project, the Hello World Application, which is tradition

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‫when starting a new programming language.

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‫So the idea is to just write a hello world code that will then display in some fashion.

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‫In our case, it's going to display it onto the console, which is a little software that will pop up

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‫and you will see how that works in a bit.

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‫So once you have Visual Studio 2019 opened, you will find this option here to create a new project,

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‫which is exactly what we're going to do.

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‫So once you click on it, you will find this screen here where you can then select either the recent

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‫templates.

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‫In my case, it says console application.

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‫In your case, it will probably not be available here because you have not created a recent project,

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‫but you can select it here from the right hand side.

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‫And what is visible for you here depends on the packages that you have installed in your Visual Studio

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‫installer.

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‫Like we did a couple of videos back.

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‫So here you can now select this C-sharp console application.

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‫It has to say C-sharp here at the top for this to be the C-sharp version of it, because there's also

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‫a visual basic console application and I even believe an F version as well somewhere down there.

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‫So what's interesting for us is going to be this one here, which says a project for creating a command

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‫line application that can run on the Ethernet core on Windows, Linux and Mac OS.

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‫So that's the one that I want to select.

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‫By the way, if you had Visual Studio open like this already, as you probably did, then what you can

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‫do is you can go to file new and project and from there you can also select this console application.

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‫So here the window will pop up in the same manner.

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‫So if you select any of the other options here, what will change is going to be the code that will

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‫be auto generated for you.

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‫So what this basically does is it just generates a bunch of code for us and we don't even have to type

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‫it manually ourselves.

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‫Of course, you could build an entire software without using an IDE such as Visual Studio and that would

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‫be fine as well.

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‫But that's a lot more difficult because there are a lot of errors that could appear and you wouldn't

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‫even notice them because the it doesn't support you as well as you would have to write all of the code

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‫manually yourself and you will see what I mean with this in a second.

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‫So let's just select this console application, click next and then give it a name and I'm going to

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‫call this one Hello World.

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‫It will be stored in this location as you see here, and that will be the solution name.

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‫So you could change that if you wanted to.

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‫So now let's press next.

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‫And here we can select the target framework and I'm going to use dot net 5.0, which is the current

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‫version.

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‫So in case that it says dot net code 3.1 long term support, that would work as well.

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‫It would basically do the same thing, but I would recommend to just use dot net five because that's

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‫the latest version of the dot net framework and it's a super powerful framework, which basically means

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‫that there is a lot of code already surrounding it and you can just tap into the features that you want

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‫to use for your own software, and that's what we're going to do.

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‫So we don't want to write everything from scratch.

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‫We want to have a framework that really helps us out here, and that's generally a good approach.

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‫So now let's go ahead and create this, and this will then automatically generate a program for us.

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‫So there we are by default.

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‫It generated this program CSS file for me and the project itself.

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‫So if we look at the project, you can right click here and you can go over to your open folder and

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‫file explorer and that will then show you all of the files that have been generated.

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‫So it generated this Helloworld folder with this SLN, which is the Visual Studio Solution file, which

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‫basically would open up this project that we have there.

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‫And then if you go deeper, you will find the bin folder with the debug folder as well as the object

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‫folder, also with the debug and a couple of files.

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‫And then what's interesting is this program CSS.

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‫So if you double click on it, it will automatically open up in Visual Studio as you see here.

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‫But you can also open it by right clicking and editing here, for example, and then it will open up

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‫in the editor.

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‫So here you see that this is where you could also write your code directly in the editor.

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‫But the beauty really is in Visual Studio code that you have this color coding which helps you out as

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‫well as it understands if we have an error in our code.

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‫So for example, if I forget the semicolon here at the end it will display, hey, there is something

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‫missing.

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‫And it even says semicolon was expected.

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‫So let me add that back there.

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‫All right.

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‫So now what's going on on the screen?

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‫What we have this using system, what that does is it basically says, I want to use the namespace called

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‫system.

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‫And this namespace system has a bunch of different classes which you can then use.

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‫So basically functionality that you can then use.

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‫And this using system has, for example, details about what a console is.

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‫So once you hover over this console keyword, you will see that it says class system, dot console.

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‫So there is this namespace called system which contains a bunch of classes and we can use those now

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‫in our project because we just added the namespace and we can later on add namespaces for example,

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‫if you want to send emails and we can just add an email namespace here and then that will give us a

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‫bunch of classes that we can use in order to, for example, send emails with our software.

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‫Now we're creating our own namespace called Helloworld, and instead of this namespace called Helloworld,

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‫we have our own class that we called program, and that was done for us by default because we didn't

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‫change this name ourselves.

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‫But that's fine.

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‫So you can see it says Class Hello World Program.

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‫Similar to what we have here, once we hover over console where it says class system that console.

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‫So every single class has a certain functionality and in our case, this class program here has just

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‫one functionality where it goes into this main method.

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‫So this is the entry point of any program.

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‫And then here, I'm just going to add a comment here, entry point of our program.

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‫So this here is a comment.

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‫I'm using double slashes here in order to make sure that I am writing a comment that will not impact

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‫our software whatsoever.

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‫So our program will do exactly as it did without this line of code.

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‫But what this line of code does for us is it helps us to understand what's happening in the code so

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‫we as programmers can just add this, and somebody else who reads our code later on can understand what

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‫we wrote there.

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‫Because the more complex your software gets, the more difficult it is to understand and the more important

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‫it is that you have these kind of comments that help you understand what every single line does.

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‫So that's what I would recommend that you do if you really want to learn quicker, is that you add a

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‫comment after every single line that you are writing.

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‫If you don't fully understand it, you try to write a comment about trying to understand what's written

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‫there by maybe rewatching a certain part of the video and so forth.

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‫So this is the entry point of our program.

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‫We're not going to look into too much what's the static means?

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‫And for now just means that we don't need to create an object in order to run this method.

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‫What that means, it would be way too much for at this point of the course.

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‫We're going to see what that means later on in the course.

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‫Then we say that this method is void so it doesn't return anything.

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‫We're going to see what that means once we're looking into methods and then this is the actual method,

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‫we're going to see what methods are later on as well.

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‫So basically we're saying, okay, this is the entry point of our program and once we run our program,

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‫please run whatever code is inside of these curly brackets here.

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‫And for now, what it does is it uses this console which is predefined code, which is inside of this

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‫system namespace and it uses its own method called right line, which then writes onto the console.

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‫So once you hover over this console here, it says represents the standard input output in error streams

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‫for console applications.

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‫So now if you run our program, we will see that it automatically opens up this little window and it

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‫says Hello world here.

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‫So this is what our software now does for us.

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‫And where does it come from?

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‫Well, it came from hello world bin debug dot net 5.0.

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‫Hello World X.

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‫Okay, so that file was executed for us and it said hello world.

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‫So now instead of saying hello world, let's add another line.

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‫So let's just copy this line here, let's add it underneath and say something like, Hello, Dennis.

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‫In my case it's going to say Hello, Dennis.

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‫And in your case, what I would like you to do is I would like you to change that, to say hello and

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‫then your name.

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‫Okay.

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‫And then now it will say hello world in one line.

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‫And in the second line it will say Hello, Dennis.

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‫So let's run the software real quick and you see it says Hello World and one line.

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‫And in the second line it says, Hello, Dennis.

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‫Now what you can also see is that instead of this right line, you have these brackets.

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‫Inside of those brackets, you have this string.

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‫That's the official name of it, basically a piece of text where you need to surround it with quotation

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‫marks, as you see here.

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‫And then we have a closing bracket as well as a semicolon at the end.

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‫And semicolon is very important in programming, at least in most programming languages.

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‫There are some programming languages that are not using a semicolon at the end of each line, but in

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‫C sharp it's required.

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‫So we're basically saying, okay, this is where the statement ends.

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‫So here we are finishing it with a semicolon.

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‫So the same goes here.

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‫We're finishing the statement and we're adding a semicolon.

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‫This might look a little weird at the beginning, but no worries.

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‫You're going to get a hang of it later on.

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‫So now what you can also see is that there are a bunch of curly brackets.

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‫So here this namespace hello world has a curly bracket and opening one here and the closing one down

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‫there, which is automatically also marked once I mark one of them.

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‫So it says, okay, this part is now my body.

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‫So this is the part that is inside of me.

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‫So here the class, all of this code here is inside of the Helloworld namespace and then this stuff

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‫here is inside of the class program.

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‫And then we have this method called Main and inside of it is that code here.

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‫So at the left hand side you can even see these minuses here and you can collapse the entries, the

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‫code by just pressing on them.

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‫And this will then.

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‫Shrink your code, but the code is still there.

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‫Now, another very short, very interesting thing that I wanted to show you is that if you open the

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‫folder in the file Explorer and you actually go to bin debug dot net five, you will find that there

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‫is this helloworld exe file.

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‫So if you click on that, it will also open the console.

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‫But unfortunately it's closing straightaway.

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‫So if you want to make sure that it stays open, then you need to add this line here which says console

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‫dot read.

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‫So what that will do is it will read the next character from the standard input stream.

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‫And we also need to use these brackets because we're actually calling a method.

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‫As I said, we're going to see what methods are later on and we need a semicolon in order to finish

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‫this statement.

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‫So now if you run this code, it will run as it did before, but it's going to stay open and let me

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‫press a key, and then it will close, so to speak, even though in Visual Studio, by default, it

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‫leaves this window open for us for debugging.

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‫You can turn this off if you go to this setting here.

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‫So tools, options, debugging automatically close to console with debugging stops.

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‫So feel free to make that change.

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‫But what's interesting now is if you go back to our hello world exa that's the window is now staying

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‫open so it stays open.

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‫And now once we press the key, it closes.

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‫Okay.

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‫So this is our software.

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‫So now we wrote our own Excel file, and we can use this Excel file in order to impress our friends.

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‫All right.

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‫So that's it for this video.

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‫See you in the next one.